<PAGE>

    As filed with the Securities and Exchange Commission on August 2, 1999

                                                    Registration No. 333-

==============================================================================

                      SECURITIES AND EXCHANGE COMMISSION

                            WASHINGTON, D.C. 20549

                              -------------------

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     Under
                          THE SECURITIES ACT OF 1933

                              -------------------

                       FOCAL COMMUNICATIONS CORPORATION
            (Exact Name of Registrant as Specified in Its Charter)

<TABLE>
<S>                                                 <C>
              Delaware                                          36-4167094
(State or Other Jurisdiction of Incorporation)      (I.R.S. Employer Identification No.)
</TABLE>

                     200 North LaSalle Street, Suite 1100
                            Chicago, Illinois 60601
                   (Address of Principal Executive Offices)

                  1998 Equity Plan for Non-Employee Directors
                           (Full Title of the Plan)

                              -------------------

                               Joseph A. Beatty
             Executive Vice President and Chief Financial Officer
                       Focal Communications Corporation
                     200 North LaSalle Street, Suite 1100
                            Chicago, Illinois 60601
                    (Name and Address of Agent For Service)

                                (312) 895-8400
         (Telephone Number, Including Area Code, of Agent For Service)

                                With a copy to:
                             Elizabeth C. Kitslaar
                          Jones, Day, Reavis & Pogue
                                77 West Wacker
                         Chicago, Illinois 60601-1692
                                (312) 269-4114

                              -------------------

<TABLE>
<CAPTION>
                                           CALCULATION OF REGISTRATION FEE
==========================================================================================================================

                                                               Proposed            Proposed
                                                               Maximum              Maximum
                                             Amount To Be    Offering Price        Aggregate              Amount Of
   Title Of Securities To Be Registered       Registered     Per Share/(1)/     Offering Price(/1)/    Registration Fee
==========================================================================================================================
<S>                                          <C>             <C>                <C>                   <C>
Common Stock, par value $.01 per share       150,000 shares    $17.98            $ 2,697,000.00        $ 750.00
==========================================================================================================================
</TABLE>
(1)  Estimated solely for the purpose of calculating the amount of the
     registration fee, pursuant to paragraphs (c) and (h) of Rule 457 under the
     Securities Act, on the basis of the average of high and low sale prices of
     the shares of Common Stock, par value $.01 per share, of the Company (the
     "Common Stock"), on the Nasdaq National Market on July 28, 1999.

==============================================================================
<PAGE>

                                    PART II

              Information Required in the Registration Statement

Item 3.   Incorporation of Documents by Reference

          The following documents filed by Focal Communications Corporation (the
"Company" or the "Registrant") with the Securities and Exchange Commission (the
"Commission") are incorporated by reference in this Registration Statement:

               (a)  The Company's Annual Report on Form 10-K for the year ended
          December 31, 1998, filed with the Commission on March 31, 1999, as
          amended on Form 10-K/A, filed with the Commission on April 7, 1999;

               (b)  The Company's Quarterly Report on Form 10-Q for the quarter
          ended March 31, 1999, filed with the Commission on May 7, 1999, as
          amended on Form 10- Q/A, filed with the Commission on July 6, 1999;
          and

               (c)  The description of the Company's Common Stock contained in
          the Company's Registration Statement on Form 8-A, filed with the
          Commission on July 26, 1999 (Reg. No. 000-26821) (the "Form 8-A").

          All other documents filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act subsequent to the date of this
Registration Statement and prior to the filing of a post-effective amendment
indicating that all securities offered under this Registration Statement have
been sold, or deregistering all securities then remaining unsold, are also
incorporated by reference and shall be a part hereof from the date of filing of
such documents.

          Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superceded
for purposes of this Registration Statement to the extent that a statement
contained herein or in any subsequently filed document which also is or is
deemed to be incorporated by reference herein modifies or supercedes such
statement. Any such statement so modified or superceded shall not be deemed,
except as so modified or superceded, to constitute a part of this Registration
Statement.

Item 4.   Description of Securities.

          Not applicable.

Item 5.   Interests of Named Experts and Counsel

          Not applicable.

Item 6.   Indemnification of Directors and Officers

          We have statutory authority to indemnify our officers and directors.
The applicable provisions of the Delaware General Corporation Law state that, to
the extent an officer or director is successful on the merits or otherwise, a
corporation may indemnify any person who
<PAGE>

was or is a party or who is threatened to be made a party to any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative (other than an action by or in the right of the
corporation), by reason of the fact that he is or was a director, officer,
employee or agent of the corporation or is or was serving at the request of the
corporation as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise (each, a "Person"),
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement, actually and reasonably incurred by such Person, if he acted in
good faith and in a manner he reasonably believed to be in, or not opposed to,
the best interests of the corporation and with respect to any criminal action or
proceeding, had no reasonable cause to believe his conduct was unlawful. In any
threatened, pending or completed action by or in the right of the corporation, a
corporation also may indemnify any such Person for costs actually and reasonably
incurred by him in connection with that action's defense or settlement, if he
acted in good faith and in a manner he reasonably believed to be in or not
opposed to, the best interests of the corporation; however, no indemnification
shall be made with respect to any claim, issue or matter as to which such Person
shall have been adjudged to be liable to the corporation, unless and only to the
extent that a court shall determine that such indemnity is proper.

          Under the applicable provisions of the Delaware General Corporation
Law, any indemnification shall be made by the corporation only as authorized in
the specific case upon a determination that the indemnification of the director,
officer, employee or agent is proper in the circumstances because he has met the
applicable standard of conduct. Such determination shall be made:

               (1)  By the Board of Directors by a majority vote of the
          directors who are not parties to such action, suit or proceeding, even
          if less than a quorum;

               (2)  By a committee of such directors designated by a majority
          vote of the directors who are not parties to such action, suit or
          proceeding, even if less than a quorum;

               (3)  If there are no such directors, or if such directors so
          direct, by independent legal counsel in a written opinion; or

               (4)  By the stockholders.

          The Company's certificate of incorporation and bylaws provide for
indemnification to the full extent permitted by the laws of the State of
Delaware against and with respect to threatened, pending or completed actions,
suits or proceedings arising from or alleged to arise from, a party's actions or
omissions as a director, officer, employee or agent of the Company or of any
subsidiary of the Company or of any other corporation, partnership, joint
venture, trust or other entity which he has served in such capacity at the
request of the Company if such acts or omissions occurred or were or are alleged
to have occurred, while said party was a director, officer, employee or agent of
the Company.

          In addition, the Company maintains liability insurance for its
directors and officers.

                                       2
<PAGE>

Item 7.   Exemption from Registration Claimed.

          Not applicable.

Item 8.   Exhibits

Exhibit Number      Description
--------------      -----------

4.1                 Amended and Restated Certificate of Incorporation
                    (incorporated by reference to Exhibit No. 3.3 to the
                    Company's Registration Statement on Form S-1 originally
                    filed with the Commission on May 7, 1999 (Registration No.
                    333-77995) (the "S-1"))

4.2                 Amended and Restated By-Laws (incorporated by reference to
                    Exhibit No. 3.5 of the S-1)

4.3                 Indenture with Harris Trust and Savings Bank, dated February
                    18, 1998 (incorporated by reference to Exhibit No. 4.1 to
                    the Company's Registration Statement on Form S-4 originally
                    filed with the Commission on August 13, 1998 (Registration
                    No. 333-49397) (the "S-4"))

4.4                 Initial Global 12.125% Senior Discount Note Due February 15,
                    2008, dated February 18, 1998 (incorporated by reference to
                    Exhibit No. 4.2 of the S-4)

4.5                 Stock Purchase Agreement with Madison Dearborn Capital
                    Partners, L.P., Frontenac VI, L.P., Battery Ventures III,
                    L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty, and
                    Robert C. Taylor Jr., dated November 27, 1996 (incorporated
                    by reference to Exhibit No. 4.5 of the S-4)

4.6                 Amendment No. 1 to Stock Purchase Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated January 23, 1998
                    (incorporated by reference to Exhibit No. 4.6 of the S-4)

4.7                 Amendment No. 2 to Stock Purchase Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of August 21,
                    1998 (incorporated by reference to Exhibit No. 4.8 to the
                    Company's Quarterly Report on Form 10-Q for the period
                    ending September 30, 1998, originally filed with the
                    Securities and Exchange Commission on November 16, 1998 (the
                    "3rd Quarter 1998 10-Q"))

4.8                 Vesting Agreement with Madison Dearborn Capital Partners,
                    L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty and
                    Robert C. Taylor, Jr., dated as of November 27, 1996
                    (incorporated by reference to Exhibit No. 4.1 of the 3rd
                    Quarter 1998 10-Q)

                                       3
<PAGE>

4.9                 Vesting Agreement with Frontenac VI, L.P., Brian F. Addy,
                    John R. Barnicle, Joseph Beatty and Robert C. Taylor, Jr.,
                    dated as of November 27, 1996 (incorporated by reference to
                    Exhibit No. 4.2 of the 3rd Quarter 1998 10-Q)

4.10                Vesting Agreement with Battery Ventures III, L.P., Brian F.
                    Addy, John R. Barnicle, Joseph Beatty and Robert C. Taylor,
                    Jr., dated as of November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.3 of the 3rd Quarter 1998 10-Q)

4.11                Amendment No. 1 to Vesting Agreement and Consent as of
                    August 21, 1998, between the Company and Madison Dearborn
                    Capital Partners, L.P., Frontenac VI, L.P., Battery Ventures
                    III, L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty
                    and Robert C. Taylor, Jr., dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.4 of the 3rd
                    Quarter 1998 10-Q)

4.12                Amendment No. 1 to Vesting Agreement and Consent as of
                    August 21, 1998, between the Company and Madison Dearborn
                    Capital Partners, L.P., Frontenac VI, L.P., Battery Ventures
                    III, L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty
                    and Robert C. Taylor, Jr., dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.5 of the 3rd
                    Quarter 1998 10-Q)

4.13                Amendment No. 1 to Vesting Agreement and Consent as of
                    August 21, 1998, between the Company and Madison Dearborn
                    Capital Partners, L.P., Frontenac VI, L.P., Battery Ventures
                    III, L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty
                    and Robert C. Taylor, Jr., dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.6 of the 3rd
                    Quarter 1998 10-Q)

4.14                Form of Restricted Stock Agreement, dated September 30, 1998
                    between the Company and each of Brian F. Addy, John R.
                    Barnicle, Joseph Beatty, and Robert C. Taylor, Jr.
                    (incorporated by reference to Exhibit No. 4.7 of the 3rd
                    Quarter 1998 10-Q)

4.15                Stockholders Agreement with Madison Dearborn Capital
                    Partners, L.P., Frontenac VI, L.P., Battery Ventures III,
                    L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty, and
                    Robert C. Taylor Jr., dated November 27, 1996 (incorporated
                    by reference to Exhibit No. 4.11 of the S-4)

4.16                Amendment No. 1 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of July 7, 1998
                    (incorporated by reference to Exhibit No. 4.9 of the 3rd
                    Quarter 1998 10-Q)

                                       4
<PAGE>

4.17                Amendment No. 2 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of August 21,
                    1998 (incorporated by reference to Exhibit No. 4.10 of the
                    3rd Quarter 1998 10-Q)

4.18                Amendment No. 3 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of February 16,
                    1999 (incorporated by reference to Exhibit No. 4.16 to the
                    Company's Annual Report on Form 10-K for year ended December
                    31, 1998 originally filed with the Commission on March 31,
                    1998 (the "1998 10-K"))

4.19                Executive Stock Agreement and Employment Agreement with
                    Brian F. Addy, dated November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.12 of the S-4)

4.20                Executive Stock Agreement and Employment Agreement with John
                    R. Barnicle, dated November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.13 of the S-4)

4.21                Executive Stock Agreement and Employment Agreement with
                    Joseph A. Beatty, dated November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.14 of the S-4)

4.22                Executive Stock Agreement and Employment Agreement with
                    Robert C. Taylor, Jr., dated November 27, 1996 (incorporated
                    by reference to Exhibit No. 4.15 of the S-4)

4.23                Amendment No. 1 to Executive Employment Agreement and
                    Consent with Brian F. Addy, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.11 of the 3rd
                    Quarter 1998 10-Q)

4.24                Amendment No. 1 to Executive Employment Agreement and
                    Consent with John R. Barnicle, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.12 of the 3rd
                    Quarter 1998 10-Q)

4.25                Amendment No. 1 to Executive Employment Agreement and
                    Consent with Joseph Beatty, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.13 of the 3rd
                    Quarter 1998 10-Q)

4.26                Amendment No. 1 to Executive Employment Agreement and
                    Consent with Robert C. Taylor, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.14 of the 3rd
                    Quarter 1998 10-Q)

4.27                Registration Agreement with Madison Dearborn Capital
                    Partners, L.P., Frontenac VI, L.P., Battery Ventures III,
                    L.P., Brian F. Addy, John R.

                                       5
<PAGE>

                    Barnicle, Joseph Beatty, and Robert C. Taylor Jr., dated
                    November 27, 1996 (incorporated by reference to Exhibit No.
                    4.16 of the S-4)

4.28                Amendment No. 1 to Registration Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of August 21,
                    1998 (incorporated by reference to Exhibit No. 4.15 of the
                    3rd Quarter 1998 10-Q)

4.29                Amendment No. 4 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty and Robert C. Taylor, Jr., dated as of May 21, 1999
                    (incorporated by reference to Exhibit No. 4.27 of the S-1)

4.30                1998 Equity Plan for Non-Employee Directors (incorporated by
                    reference to Exhibit No. 10.9 of the 3rd Quarter 1998 10-Q)

4.31                Form of Nonqualified Stock Option Agreement for use in
                    connection with the 1998 Equity Plan for Non-Employee
                    Directors

4.32                Form of Participation Agreement for use in connection with
                    the 1998 Equity Plan for Non-Employee Directors

5.1                 Opinion of Jones, Day, Reavis & Pogue

23.1                Consent of Jones, Day, Reavis & Pogue (included in Exhibit
                    5.1)

23.2                Consent of Independent Public Accountants

24.1                Power of Attorney

Item 9.   Undertakings

          (a)  The undersigned Registrant hereby undertakes:

               (1)  To file, during any period in which offers or sales are
being made, a post-effective amendment to this Registration Statement:

                    (i)  To include any prospectus required by Section 10(a)(3)
               of the Securities Act;

                    (ii) To reflect in the prospectus any facts or events
               arising after the effective date of the Registration Statement
               (or the most recent post-effective amendment thereof) which,
               individually or in the aggregate, represent a fundamental change
               in the information set forth in the Registration Statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of securities offered (if the total dollar value of securities
               offered would not exceed that which

                                       6
<PAGE>

          is registered) and any deviation from the low or high of the estimated
          maximum offering range may be reflected in the form of prospectus
          filed with the Commission pursuant to Rule 424(b) if, in the
          aggregate, the changes in volume and price represent no more than 20
          percent change in the maximum aggregate offering price set forth in
          the "Calculation of Registration Fee" table in the effective
          Registration Statement.

               (iii)  To include any material information with respect to the
          plan of distribution not previously disclosed in the Registration
          Statement or any material change to such information in the
          Registration Statement;

          Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not
          apply if the Registration Statement is on Form S-3, Form S-8 or
          Form F-3, and the information required to be included in a post-
          effective amendment by those paragraphs is contained in periodic
          reports filed with or furnished to the Commission by the registrant
          pursuant to Section 13 or Section 15(d) of the Exchange Act that are
          incorporated by reference in the Registration Statement.

          (2)  That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

          (3)  To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

          (b)  The undersigned registrant hereby undertakes that, for purposes
of determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Exchange
Act (and, where applicable, each filing of an employee benefit plan's annual
report pursuant to Section 15(d) of the Exchange Act) that is incorporated by
reference in the Registration Statement shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

          (c)  Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred
or paid by a director, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

                                       7
<PAGE>

                                  SIGNATURES

     Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Chicago, State of Illinois, on August 2, 1999.


                              FOCAL COMMUNICATIONS CORPORATION


                              By:  /s/ Robert C. Taylor
                                 -------------------------------
                                       Robert C. Taylor
                                       President and Chief Executive Officer

     Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date indicated

<TABLE>
<CAPTION>
          Signature                       Title                                        Date
          ---------                       -----                                        ----
<S>                                 <C>                                           <C>
  /s/ Robert C. Taylor, Jr.         Director, President and Chief                 August 2, 1999
-----------------------------
      Robert C. Taylor, Jr.              Executive Officer


  /s/ John R. Barnicle                 Director, Executive Vice                   August 2, 1999
------------------------------
      John R. Barnicle                   President and Chief
                                          Operating Officer


  /s/ Joseph A. Beatty              Executive Vice President and                  August 2, 1999
------------------------------
      Joseph A. Beatty                  Chief Financial Officer


  /s/ Gregory J. Swanson                      Controller                          August 2, 1999
----------------------------
      Gregory J. Swanson
</TABLE>

______________________________________________________________________________

                                       8
<PAGE>

<TABLE>
<S>                                         <C>                   <C>
   /s/ James E. Crawford, III               Director              August 2, 1999
-------------------------------
       James E. Crawford, III


   /s/ John A. Edwardson                    Director              August 2, 1999
-----------------------------
       John A. Edwardson


   /s/ Paul J. Finnegan                     Director              August 2, 1999
--------------------------------
       Paul J. Finnegan


   /s/ Richard D. Frisbie                   Director              August 2, 1999
-------------------------------
       Richard D. Frisbie


   /s/ James N. Perry, Jr.                  Director              August 2, 1999
--------------------------------
       James N. Perry, Jr.


   /s/ Paul G. Yovovich                     Director              August 2, 1999
------------------------------
       Paul G. Yovovich
</TABLE>


* Joseph A. Beatty, the undersigned attorney-in-fact, by signing his name
hereto, does hereby sign and execute this Registration Statement on behalf of
the above indicated Registrant and officers and directors thereof (constituting
a majority of the directors) pursuant to a Power of Attorney filed with the
Securities and Exchange Commission.


August 2, 1999                      By: /s/ Joseph A. Beatty
                                       ---------------------------------------
                                            Joseph A. Beatty
                                            Executive Vice President and Chief
                                             Financial Officer

                                       9
<PAGE>

                                 EXHIBIT INDEX
<TABLE>
<CAPTION>
                                                                          Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
<S>               <C>                                                     <C>
4.1               Amended and Restated Certificate of Incorporation       Incorporated by
                  (incorporated by reference to Exhibit No. 3.3 to        reference
                  the Company's Registration Statement on Form S-1
                  originally filed with the Commission on May 7,
                  1999 (Registration No. 333-77995) (the "S-1"))

4.2               Amended and Restated By-Laws (incorporated by           Incorporated by
                  reference to Exhibit No. 3.5 to the S-1)                reference

4.3               Indenture with Harris Trust and Savings Bank,           Incorporated by
                  dated February 18, 1998 (incorporated by                reference
                  reference to Exhibit No. 4.1 to the Company's
                  Registration Statement on Form S-4 originally
                  filed with the Securities and Exchange Commission
                  on August 13, 1998 (Registration No. 333-49397)
                  (the "S-4"))

4.4               Initial Global 12.125% Senior Discount Note Due         Incorporated by
                  February 15, 2008, dated February 18, 1998              reference
                  (incorporated by reference to Exhibit No. 4.2 of
                  the S-4)

4.5               Stock Purchase Agreement with Madison Dearborn          Incorporated by
                  Capital Partners, L.P., Frontenac VI, L.P.,             reference
                  Battery Ventures III, L.P., Brian F. Addy, John
                  R. Barnicle, Joseph Beatty, and Robert C. Taylor
                  Jr., dated November 27, 1996 (incorporated by
                  reference to Exhibit No. 4.5 of the S-4)

4.6               Amendment No. 1 to Stock Purchase Agreement with        Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated January 23, 1998
                  (incorporated by reference to Exhibit No. 4.6 of
                  the S-4)
</TABLE>

                                       10
<PAGE>

<TABLE>
<CAPTION>
                                                                          Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
<S>               <C>                                                     <C>
4.7               Amendment No. 2 to Stock Purchase Agreement with        Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.8 to the Company's Quarterly Report on Form 10-
                  Q for the period ending September 30, 1998,
                  originally filed with the Commission on November
                  16, 1998 (the "3rd Quarter 1998 10-Q"))

4.8               Vesting Agreement with Madison Dearborn Capital         Incorporated by
                  Partners, L.P., Brian F. Addy, John R. Barnicle,        reference
                  Joseph Beatty and Robert C. Taylor, Jr., dated as
                  of November 27, 1996 (incorporated by reference
                  to Exhibit No. 4.1 of the 3rd Quarter 1998 10-Q)

4.9               Vesting Agreement with Frontenac VI, L.P., Brian        Incorporated by
                  F. Addy, John R. Barnicle, Joseph Beatty and            reference
                  Robert C. Taylor, Jr., dated as of November 27,
                  1996 (incorporated by reference to Exhibit No.
                  4.2 of the 3rd Quarter 1998 10-Q)

4.10              Vesting Agreement with Battery Ventures III,            Incorporated by
                  L.P., Brian F. Addy, John R. Barnicle, Joseph           reference
                  Beatty and Robert C. Taylor, Jr., dated as of
                  November 27, 1996 (incorporated by reference to
                  Exhibit No. 4.3 of the 3rd Quarter 1998 10-Q)

4.11              Amendment No. 1 to Vesting Agreement and Consent
                  as of August 21, 1998, between the Company and
                  Madison Dearborn Capital Partners, L.P.,
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.4 of the 3rd Quarter 1998 10-Q)

4.12              Amendment No. 1 to Vesting Agreement and Consent        Incorporated by
                  as of August 21, 1998, between the Company and          reference
                  Madison Dearborn Capital Partners, L.P.,
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.5 of the 3rd Quarter 1998 10-Q)
</TABLE>

                                       11
<PAGE>

<TABLE>
<CAPTION>
                                                                          Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
<S>               <C>                                                     <C>
4.13              Amendment No. 1 to Vesting Agreement and Consent        Incorporated by
                  as of August 21, 1998, between the Company and          reference
                  Madison Dearborn Capital Partners, L.P.,
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.6 of the 3rd Quarter 1998 10-Q)

4.14              Form of Restricted Stock Agreement, dated               Incorporated by
                  September 30, 1998 between the Company and each         reference
                  of Brian F. Addy, John R. Barnicle, Joseph
                  Beatty, and Robert C. Taylor, Jr. (incorporated
                  by reference to Exhibit No. 4.7 of the 3rd
                  Quarter 1998 10-Q)

4.15              Stockholders Agreement with Madison Dearborn            Incorporated by
                  Capital Partners, L.P., Frontenac VI, L.P.,             reference
                  Battery Ventures III, L.P., Brian F. Addy, John
                  R. Barnicle, Joseph Beatty, and Robert C. Taylor
                  Jr., dated November 27, 1996 (incorporated by
                  reference to Exhibit No. 4.11 of the S-4)

4.16              Amendment No. 1 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of July 7,
                  1998 (incorporated by reference to Exhibit No.
                  4.9 of the 3rd Quarter 1998 10-Q)

4.17              Amendment No. 2 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.10 of the 3rd Quarter 1998 10-Q)

4.18              Amendment No. 3 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of February
                  16, 1999 (incorporated by reference to Exhibit
                  No. 4.16 to the Company's Annual Report on Form
                  10-K for year ended December 31, 1998 originally
                  filed with the Commission on March 31, 1998 (the
                  "1998 10-K"))
</TABLE>

                                       12
<PAGE>

<TABLE>
<CAPTION>
                                                                          Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
<S>               <C>                                                     <C>
4.19              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with Brian F. Addy, dated November 27,        reference
                  1996 (incorporated by reference to Exhibit No.
                  4.12 of the S-4)

4.20              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with John R. Barnicle, dated November         reference
                  27, 1996 (incorporated by reference to Exhibit
                  No. 4.13 of the S-4)

4.21              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with Joseph A. Beatty, dated November         reference
                  27, 1996 (incorporated by reference to Exhibit
                  No. 4.14 of the S-4)

4.22              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with Robert C. Taylor, Jr., dated             reference
                  November 27, 1996 (incorporated by reference to
                  Exhibit No. 4.15 of the S-4)

4.23              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with Brian F. Addy, dated as of             reference
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.11 of the 3rd Quarter 1998 10-Q)

4.24              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with John R. Barnicle, dated as of          refereence
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.12 of the 3rd Quarter 1998 10-Q)

4.25              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with Joseph Beatty, dated as of             reference
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.13 of the 3rd Quarter 1998 10-Q)

4.26              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with Robert C. Taylor, dated as of          reference
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.14 of the 3rd Quarter 1998 10-Q)

4.27              Registration Agreement with Madison Dearborn            Incorporated by
                  Capital Partners, L.P., Frontenac VI, L.P.,             reference
                  Battery Ventures III, L.P., Brian F. Addy, John
                  R. Barnicle, Joseph Beatty, and Robert C. Taylor
                  Jr., dated November 27, 1996 (incorporated by
                  reference to Exhibit No. 4.16 of the S-4)
</TABLE>

                                       13
<PAGE>

<TABLE>
<CAPTION>
                                                                          Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
<S>               <C>                                                     <C>
4.28              Amendment No. 1 to Registration Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.15 of the 3rd Quarter 1998 10-Q)

4.29              Amendment No. 4 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of May 21,
                  1999 (incorporated by reference to Exhibit No.
                  4.27 of the S-1)

4.30              1998 Equity Plan for Non-Employee Directors             Incorporated by
                  (incorporated by reference to Exhibit No. 10.9 of       reference
                  the 3rd quarter 1998 10-Q)

4.31              Form of Nonqualified Stock Option Agreement for              15
                  use in connection with the 1998 Equity Plan for
                  Non-Employee Directors

4.32              Form of Participation Agreement for use in                   21
                  connection with the 1998 Equity Plan for Non-
                  Employee Directors

5.1               Opinion of Jones, Day, Reavis & Pogue                        23

23.1              Consent of Jones, Day, Reavis & Pogue (included              23
                  in Exhibit 5.1)

23.2              Consent of Independent Public Accountants                    24

24.1              Power of Attorney                                            25
</TABLE>

                                       14
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 44374}]
{"company-data": {"conformed-name": "FOCAL COMMUNICATIONS CORP", "cik": "0001059130", "assigned-sic": "4812", "irs-number": "364167094", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-84259", "film-number": "99676046"}, "business-address": {"street1": "200 NORTH LASALLE ST", "city": "CHICAGO", "state": "IL", "zip": "60601", "phone": "3128958400"}, "mail-address": {"street1": "200 NORTH LASALLE ST", "city": "CHICAGO", "state": "IL", "zip": "60601"}}
As filed with the Securities and Exchange Commission on August 2, 1999

                                                    Registration No. 333-

==============================================================================

                      SECURITIES AND EXCHANGE COMMISSION

                            WASHINGTON, D.C. 20549

                              -------------------

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     Under
                          THE SECURITIES ACT OF 1933

                              -------------------

                       FOCAL COMMUNICATIONS CORPORATION
            (Exact Name of Registrant as Specified in Its Charter)
Delaware                                          36-4167094
(State or Other Jurisdiction of Incorporation)      (I.R.S. Employer Identification No.)
200 North LaSalle Street, Suite 1100
                            Chicago, Illinois 60601
                   (Address of Principal Executive Offices)

                  1998 Equity Plan for Non-Employee Directors
                           (Full Title of the Plan)

                              -------------------

                               Joseph A. Beatty
             Executive Vice President and Chief Financial Officer
                       Focal Communications Corporation
                     200 North LaSalle Street, Suite 1100
                            Chicago, Illinois 60601
                    (Name and Address of Agent For Service)

                                (312) 895-8400
         (Telephone Number, Including Area Code, of Agent For Service)

                                With a copy to:
                             Elizabeth C. Kitslaar
                          Jones, Day, Reavis & Pogue
                                77 West Wacker
                         Chicago, Illinois 60601-1692
                                (312) 269-4114

                              -------------------
CALCULATION OF REGISTRATION FEE
==========================================================================================================================

                                                               Proposed            Proposed
                                                               Maximum              Maximum
                                             Amount To Be    Offering Price        Aggregate              Amount Of
   Title Of Securities To Be Registered       Registered     Per Share/(1)/     Offering Price(/1)/    Registration Fee
==========================================================================================================================
Common Stock, par value $.01 per share       150,000 shares    $17.98            $ 2,697,000.00        $ 750.00
==========================================================================================================================
(1)  Estimated solely for the purpose of calculating the amount of the
     registration fee, pursuant to paragraphs (c) and (h) of Rule 457 under the
     Securities Act, on the basis of the average of high and low sale prices of
     the shares of Common Stock, par value $.01 per share, of the Company (the
     "Common Stock"), on the Nasdaq National Market on July 28, 1999.

==============================================================================
PART II

              Information Required in the Registration Statement

Item 3.   Incorporation of Documents by Reference

          The following documents filed by Focal Communications Corporation (the
"Company" or the "Registrant") with the Securities and Exchange Commission (the
"Commission") are incorporated by reference in this Registration Statement:

               (a)  The Company's Annual Report on Form 10-K for the year ended
          December 31, 1998, filed with the Commission on March 31, 1999, as
          amended on Form 10-K/A, filed with the Commission on April 7, 1999;

               (b)  The Company's Quarterly Report on Form 10-Q for the quarter
          ended March 31, 1999, filed with the Commission on May 7, 1999, as
          amended on Form 10- Q/A, filed with the Commission on July 6, 1999;
          and

               (c)  The description of the Company's Common Stock contained in
          the Company's Registration Statement on Form 8-A, filed with the
          Commission on July 26, 1999 (Reg. No. 000-26821) (the "Form 8-A").

          All other documents filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act subsequent to the date of this
Registration Statement and prior to the filing of a post-effective amendment
indicating that all securities offered under this Registration Statement have
been sold, or deregistering all securities then remaining unsold, are also
incorporated by reference and shall be a part hereof from the date of filing of
such documents.

          Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superceded
for purposes of this Registration Statement to the extent that a statement
contained herein or in any subsequently filed document which also is or is
deemed to be incorporated by reference herein modifies or supercedes such
statement. Any such statement so modified or superceded shall not be deemed,
except as so modified or superceded, to constitute a part of this Registration
Statement.

Item 4.   Description of Securities.

          Not applicable.

Item 5.   Interests of Named Experts and Counsel

          Not applicable.

Item 6.   Indemnification of Directors and Officers

          We have statutory authority to indemnify our officers and directors.
The applicable provisions of the Delaware General Corporation Law state that, to
the extent an officer or director is successful on the merits or otherwise, a
corporation may indemnify any person who
was or is a party or who is threatened to be made a party to any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative (other than an action by or in the right of the
corporation), by reason of the fact that he is or was a director, officer,
employee or agent of the corporation or is or was serving at the request of the
corporation as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise (each, a "Person"),
against expenses (including attorneys' fees), judgments, fines and amounts paid
in settlement, actually and reasonably incurred by such Person, if he acted in
good faith and in a manner he reasonably believed to be in, or not opposed to,
the best interests of the corporation and with respect to any criminal action or
proceeding, had no reasonable cause to believe his conduct was unlawful. In any
threatened, pending or completed action by or in the right of the corporation, a
corporation also may indemnify any such Person for costs actually and reasonably
incurred by him in connection with that action's defense or settlement, if he
acted in good faith and in a manner he reasonably believed to be in or not
opposed to, the best interests of the corporation; however, no indemnification
shall be made with respect to any claim, issue or matter as to which such Person
shall have been adjudged to be liable to the corporation, unless and only to the
extent that a court shall determine that such indemnity is proper.

          Under the applicable provisions of the Delaware General Corporation
Law, any indemnification shall be made by the corporation only as authorized in
the specific case upon a determination that the indemnification of the director,
officer, employee or agent is proper in the circumstances because he has met the
applicable standard of conduct. Such determination shall be made:

               (1)  By the Board of Directors by a majority vote of the
          directors who are not parties to such action, suit or proceeding, even
          if less than a quorum;

               (2)  By a committee of such directors designated by a majority
          vote of the directors who are not parties to such action, suit or
          proceeding, even if less than a quorum;

               (3)  If there are no such directors, or if such directors so
          direct, by independent legal counsel in a written opinion; or

               (4)  By the stockholders.

          The Company's certificate of incorporation and bylaws provide for
indemnification to the full extent permitted by the laws of the State of
Delaware against and with respect to threatened, pending or completed actions,
suits or proceedings arising from or alleged to arise from, a party's actions or
omissions as a director, officer, employee or agent of the Company or of any
subsidiary of the Company or of any other corporation, partnership, joint
venture, trust or other entity which he has served in such capacity at the
request of the Company if such acts or omissions occurred or were or are alleged
to have occurred, while said party was a director, officer, employee or agent of
the Company.

          In addition, the Company maintains liability insurance for its
directors and officers.

                                       2
Item 7.   Exemption from Registration Claimed.

          Not applicable.

Item 8.   Exhibits

Exhibit Number      Description
--------------      -----------

4.1                 Amended and Restated Certificate of Incorporation
                    (incorporated by reference to Exhibit No. 3.3 to the
                    Company's Registration Statement on Form S-1 originally
                    filed with the Commission on May 7, 1999 (Registration No.
                    333-77995) (the "S-1"))

4.2                 Amended and Restated By-Laws (incorporated by reference to
                    Exhibit No. 3.5 of the S-1)

4.3                 Indenture with Harris Trust and Savings Bank, dated February
                    18, 1998 (incorporated by reference to Exhibit No. 4.1 to
                    the Company's Registration Statement on Form S-4 originally
                    filed with the Commission on August 13, 1998 (Registration
                    No. 333-49397) (the "S-4"))

4.4                 Initial Global 12.125% Senior Discount Note Due February 15,
                    2008, dated February 18, 1998 (incorporated by reference to
                    Exhibit No. 4.2 of the S-4)

4.5                 Stock Purchase Agreement with Madison Dearborn Capital
                    Partners, L.P., Frontenac VI, L.P., Battery Ventures III,
                    L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty, and
                    Robert C. Taylor Jr., dated November 27, 1996 (incorporated
                    by reference to Exhibit No. 4.5 of the S-4)

4.6                 Amendment No. 1 to Stock Purchase Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated January 23, 1998
                    (incorporated by reference to Exhibit No. 4.6 of the S-4)

4.7                 Amendment No. 2 to Stock Purchase Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of August 21,
                    1998 (incorporated by reference to Exhibit No. 4.8 to the
                    Company's Quarterly Report on Form 10-Q for the period
                    ending September 30, 1998, originally filed with the
                    Securities and Exchange Commission on November 16, 1998 (the
                    "3rd Quarter 1998 10-Q"))

4.8                 Vesting Agreement with Madison Dearborn Capital Partners,
                    L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty and
                    Robert C. Taylor, Jr., dated as of November 27, 1996
                    (incorporated by reference to Exhibit No. 4.1 of the 3rd
                    Quarter 1998 10-Q)

                                       3
4.9                 Vesting Agreement with Frontenac VI, L.P., Brian F. Addy,
                    John R. Barnicle, Joseph Beatty and Robert C. Taylor, Jr.,
                    dated as of November 27, 1996 (incorporated by reference to
                    Exhibit No. 4.2 of the 3rd Quarter 1998 10-Q)

4.10                Vesting Agreement with Battery Ventures III, L.P., Brian F.
                    Addy, John R. Barnicle, Joseph Beatty and Robert C. Taylor,
                    Jr., dated as of November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.3 of the 3rd Quarter 1998 10-Q)

4.11                Amendment No. 1 to Vesting Agreement and Consent as of
                    August 21, 1998, between the Company and Madison Dearborn
                    Capital Partners, L.P., Frontenac VI, L.P., Battery Ventures
                    III, L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty
                    and Robert C. Taylor, Jr., dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.4 of the 3rd
                    Quarter 1998 10-Q)

4.12                Amendment No. 1 to Vesting Agreement and Consent as of
                    August 21, 1998, between the Company and Madison Dearborn
                    Capital Partners, L.P., Frontenac VI, L.P., Battery Ventures
                    III, L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty
                    and Robert C. Taylor, Jr., dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.5 of the 3rd
                    Quarter 1998 10-Q)

4.13                Amendment No. 1 to Vesting Agreement and Consent as of
                    August 21, 1998, between the Company and Madison Dearborn
                    Capital Partners, L.P., Frontenac VI, L.P., Battery Ventures
                    III, L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty
                    and Robert C. Taylor, Jr., dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.6 of the 3rd
                    Quarter 1998 10-Q)

4.14                Form of Restricted Stock Agreement, dated September 30, 1998
                    between the Company and each of Brian F. Addy, John R.
                    Barnicle, Joseph Beatty, and Robert C. Taylor, Jr.
                    (incorporated by reference to Exhibit No. 4.7 of the 3rd
                    Quarter 1998 10-Q)

4.15                Stockholders Agreement with Madison Dearborn Capital
                    Partners, L.P., Frontenac VI, L.P., Battery Ventures III,
                    L.P., Brian F. Addy, John R. Barnicle, Joseph Beatty, and
                    Robert C. Taylor Jr., dated November 27, 1996 (incorporated
                    by reference to Exhibit No. 4.11 of the S-4)

4.16                Amendment No. 1 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of July 7, 1998
                    (incorporated by reference to Exhibit No. 4.9 of the 3rd
                    Quarter 1998 10-Q)

                                       4
4.17                Amendment No. 2 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of August 21,
                    1998 (incorporated by reference to Exhibit No. 4.10 of the
                    3rd Quarter 1998 10-Q)

4.18                Amendment No. 3 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of February 16,
                    1999 (incorporated by reference to Exhibit No. 4.16 to the
                    Company's Annual Report on Form 10-K for year ended December
                    31, 1998 originally filed with the Commission on March 31,
                    1998 (the "1998 10-K"))

4.19                Executive Stock Agreement and Employment Agreement with
                    Brian F. Addy, dated November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.12 of the S-4)

4.20                Executive Stock Agreement and Employment Agreement with John
                    R. Barnicle, dated November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.13 of the S-4)

4.21                Executive Stock Agreement and Employment Agreement with
                    Joseph A. Beatty, dated November 27, 1996 (incorporated by
                    reference to Exhibit No. 4.14 of the S-4)

4.22                Executive Stock Agreement and Employment Agreement with
                    Robert C. Taylor, Jr., dated November 27, 1996 (incorporated
                    by reference to Exhibit No. 4.15 of the S-4)

4.23                Amendment No. 1 to Executive Employment Agreement and
                    Consent with Brian F. Addy, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.11 of the 3rd
                    Quarter 1998 10-Q)

4.24                Amendment No. 1 to Executive Employment Agreement and
                    Consent with John R. Barnicle, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.12 of the 3rd
                    Quarter 1998 10-Q)

4.25                Amendment No. 1 to Executive Employment Agreement and
                    Consent with Joseph Beatty, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.13 of the 3rd
                    Quarter 1998 10-Q)

4.26                Amendment No. 1 to Executive Employment Agreement and
                    Consent with Robert C. Taylor, dated as of August 21, 1998
                    (incorporated by reference to Exhibit No. 4.14 of the 3rd
                    Quarter 1998 10-Q)

4.27                Registration Agreement with Madison Dearborn Capital
                    Partners, L.P., Frontenac VI, L.P., Battery Ventures III,
                    L.P., Brian F. Addy, John R.

                                       5
Barnicle, Joseph Beatty, and Robert C. Taylor Jr., dated
                    November 27, 1996 (incorporated by reference to Exhibit No.
                    4.16 of the S-4)

4.28                Amendment No. 1 to Registration Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty, and Robert C. Taylor Jr., dated as of August 21,
                    1998 (incorporated by reference to Exhibit No. 4.15 of the
                    3rd Quarter 1998 10-Q)

4.29                Amendment No. 4 to Stockholders Agreement with Madison
                    Dearborn Capital Partners, L.P., Frontenac VI, L.P., Battery
                    Ventures III, L.P., Brian F. Addy, John R. Barnicle, Joseph
                    Beatty and Robert C. Taylor, Jr., dated as of May 21, 1999
                    (incorporated by reference to Exhibit No. 4.27 of the S-1)

4.30                1998 Equity Plan for Non-Employee Directors (incorporated by
                    reference to Exhibit No. 10.9 of the 3rd Quarter 1998 10-Q)

4.31                Form of Nonqualified Stock Option Agreement for use in
                    connection with the 1998 Equity Plan for Non-Employee
                    Directors

4.32                Form of Participation Agreement for use in connection with
                    the 1998 Equity Plan for Non-Employee Directors

5.1                 Opinion of Jones, Day, Reavis & Pogue

23.1                Consent of Jones, Day, Reavis & Pogue (included in Exhibit
                    5.1)

23.2                Consent of Independent Public Accountants

24.1                Power of Attorney

Item 9.   Undertakings

          (a)  The undersigned Registrant hereby undertakes:

               (1)  To file, during any period in which offers or sales are
being made, a post-effective amendment to this Registration Statement:

                    (i)  To include any prospectus required by Section 10(a)(3)
               of the Securities Act;

                    (ii) To reflect in the prospectus any facts or events
               arising after the effective date of the Registration Statement
               (or the most recent post-effective amendment thereof) which,
               individually or in the aggregate, represent a fundamental change
               in the information set forth in the Registration Statement.
               Notwithstanding the foregoing, any increase or decrease in volume
               of securities offered (if the total dollar value of securities
               offered would not exceed that which

                                       6
is registered) and any deviation from the low or high of the estimated
          maximum offering range may be reflected in the form of prospectus
          filed with the Commission pursuant to Rule 424(b) if, in the
          aggregate, the changes in volume and price represent no more than 20
          percent change in the maximum aggregate offering price set forth in
          the "Calculation of Registration Fee" table in the effective
          Registration Statement.

               (iii)  To include any material information with respect to the
          plan of distribution not previously disclosed in the Registration
          Statement or any material change to such information in the
          Registration Statement;

          Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not
          apply if the Registration Statement is on Form S-3, Form S-8 or
          Form F-3, and the information required to be included in a post-
          effective amendment by those paragraphs is contained in periodic
          reports filed with or furnished to the Commission by the registrant
          pursuant to Section 13 or Section 15(d) of the Exchange Act that are
          incorporated by reference in the Registration Statement.

          (2)  That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

          (3)  To remove from registration by means of a post-effective
amendment any of the securities being registered which remain unsold at the
termination of the offering.

          (b)  The undersigned registrant hereby undertakes that, for purposes
of determining any liability under the Securities Act, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Exchange
Act (and, where applicable, each filing of an employee benefit plan's annual
report pursuant to Section 15(d) of the Exchange Act) that is incorporated by
reference in the Registration Statement shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

          (c)  Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred
or paid by a director, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

                                       7
SIGNATURES

     Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Chicago, State of Illinois, on August 2, 1999.

                              FOCAL COMMUNICATIONS CORPORATION

                              By:  /s/ Robert C. Taylor
                                 -------------------------------
                                       Robert C. Taylor
                                       President and Chief Executive Officer

     Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date indicated
Signature                       Title                                        Date
          ---------                       -----                                        ----
/s/ Robert C. Taylor, Jr.         Director, President and Chief                 August 2, 1999
-----------------------------
      Robert C. Taylor, Jr.              Executive Officer

  /s/ John R. Barnicle                 Director, Executive Vice                   August 2, 1999
------------------------------
      John R. Barnicle                   President and Chief
                                          Operating Officer

  /s/ Joseph A. Beatty              Executive Vice President and                  August 2, 1999
------------------------------
      Joseph A. Beatty                  Chief Financial Officer

  /s/ Gregory J. Swanson                      Controller                          August 2, 1999
----------------------------
      Gregory J. Swanson
______________________________________________________________________________

                                       8
/s/ James E. Crawford, III               Director              August 2, 1999
-------------------------------
       James E. Crawford, III

   /s/ John A. Edwardson                    Director              August 2, 1999
-----------------------------
       John A. Edwardson

   /s/ Paul J. Finnegan                     Director              August 2, 1999
--------------------------------
       Paul J. Finnegan

   /s/ Richard D. Frisbie                   Director              August 2, 1999
-------------------------------
       Richard D. Frisbie

   /s/ James N. Perry, Jr.                  Director              August 2, 1999
--------------------------------
       James N. Perry, Jr.

   /s/ Paul G. Yovovich                     Director              August 2, 1999
------------------------------
       Paul G. Yovovich
* Joseph A. Beatty, the undersigned attorney-in-fact, by signing his name
hereto, does hereby sign and execute this Registration Statement on behalf of
the above indicated Registrant and officers and directors thereof (constituting
a majority of the directors) pursuant to a Power of Attorney filed with the
Securities and Exchange Commission.

August 2, 1999                      By: /s/ Joseph A. Beatty
                                       ---------------------------------------
                                            Joseph A. Beatty
                                            Executive Vice President and Chief
                                             Financial Officer

                                       9
EXHIBIT INDEX
Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
4.1               Amended and Restated Certificate of Incorporation       Incorporated by
                  (incorporated by reference to Exhibit No. 3.3 to        reference
                  the Company's Registration Statement on Form S-1
                  originally filed with the Commission on May 7,
                  1999 (Registration No. 333-77995) (the "S-1"))

4.2               Amended and Restated By-Laws (incorporated by           Incorporated by
                  reference to Exhibit No. 3.5 to the S-1)                reference

4.3               Indenture with Harris Trust and Savings Bank,           Incorporated by
                  dated February 18, 1998 (incorporated by                reference
                  reference to Exhibit No. 4.1 to the Company's
                  Registration Statement on Form S-4 originally
                  filed with the Securities and Exchange Commission
                  on August 13, 1998 (Registration No. 333-49397)
                  (the "S-4"))

4.4               Initial Global 12.125% Senior Discount Note Due         Incorporated by
                  February 15, 2008, dated February 18, 1998              reference
                  (incorporated by reference to Exhibit No. 4.2 of
                  the S-4)

4.5               Stock Purchase Agreement with Madison Dearborn          Incorporated by
                  Capital Partners, L.P., Frontenac VI, L.P.,             reference
                  Battery Ventures III, L.P., Brian F. Addy, John
                  R. Barnicle, Joseph Beatty, and Robert C. Taylor
                  Jr., dated November 27, 1996 (incorporated by
                  reference to Exhibit No. 4.5 of the S-4)

4.6               Amendment No. 1 to Stock Purchase Agreement with        Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated January 23, 1998
                  (incorporated by reference to Exhibit No. 4.6 of
                  the S-4)
10
Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
4.7               Amendment No. 2 to Stock Purchase Agreement with        Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.8 to the Company's Quarterly Report on Form 10-
                  Q for the period ending September 30, 1998,
                  originally filed with the Commission on November
                  16, 1998 (the "3rd Quarter 1998 10-Q"))

4.8               Vesting Agreement with Madison Dearborn Capital         Incorporated by
                  Partners, L.P., Brian F. Addy, John R. Barnicle,        reference
                  Joseph Beatty and Robert C. Taylor, Jr., dated as
                  of November 27, 1996 (incorporated by reference
                  to Exhibit No. 4.1 of the 3rd Quarter 1998 10-Q)

4.9               Vesting Agreement with Frontenac VI, L.P., Brian        Incorporated by
                  F. Addy, John R. Barnicle, Joseph Beatty and            reference
                  Robert C. Taylor, Jr., dated as of November 27,
                  1996 (incorporated by reference to Exhibit No.
                  4.2 of the 3rd Quarter 1998 10-Q)

4.10              Vesting Agreement with Battery Ventures III,            Incorporated by
                  L.P., Brian F. Addy, John R. Barnicle, Joseph           reference
                  Beatty and Robert C. Taylor, Jr., dated as of
                  November 27, 1996 (incorporated by reference to
                  Exhibit No. 4.3 of the 3rd Quarter 1998 10-Q)

4.11              Amendment No. 1 to Vesting Agreement and Consent
                  as of August 21, 1998, between the Company and
                  Madison Dearborn Capital Partners, L.P.,
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.4 of the 3rd Quarter 1998 10-Q)

4.12              Amendment No. 1 to Vesting Agreement and Consent        Incorporated by
                  as of August 21, 1998, between the Company and          reference
                  Madison Dearborn Capital Partners, L.P.,
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.5 of the 3rd Quarter 1998 10-Q)
11
Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
4.13              Amendment No. 1 to Vesting Agreement and Consent        Incorporated by
                  as of August 21, 1998, between the Company and          reference
                  Madison Dearborn Capital Partners, L.P.,
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.6 of the 3rd Quarter 1998 10-Q)

4.14              Form of Restricted Stock Agreement, dated               Incorporated by
                  September 30, 1998 between the Company and each         reference
                  of Brian F. Addy, John R. Barnicle, Joseph
                  Beatty, and Robert C. Taylor, Jr. (incorporated
                  by reference to Exhibit No. 4.7 of the 3rd
                  Quarter 1998 10-Q)

4.15              Stockholders Agreement with Madison Dearborn            Incorporated by
                  Capital Partners, L.P., Frontenac VI, L.P.,             reference
                  Battery Ventures III, L.P., Brian F. Addy, John
                  R. Barnicle, Joseph Beatty, and Robert C. Taylor
                  Jr., dated November 27, 1996 (incorporated by
                  reference to Exhibit No. 4.11 of the S-4)

4.16              Amendment No. 1 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of July 7,
                  1998 (incorporated by reference to Exhibit No.
                  4.9 of the 3rd Quarter 1998 10-Q)

4.17              Amendment No. 2 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.10 of the 3rd Quarter 1998 10-Q)

4.18              Amendment No. 3 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of February
                  16, 1999 (incorporated by reference to Exhibit
                  No. 4.16 to the Company's Annual Report on Form
                  10-K for year ended December 31, 1998 originally
                  filed with the Commission on March 31, 1998 (the
                  "1998 10-K"))
12
Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
4.19              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with Brian F. Addy, dated November 27,        reference
                  1996 (incorporated by reference to Exhibit No.
                  4.12 of the S-4)

4.20              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with John R. Barnicle, dated November         reference
                  27, 1996 (incorporated by reference to Exhibit
                  No. 4.13 of the S-4)

4.21              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with Joseph A. Beatty, dated November         reference
                  27, 1996 (incorporated by reference to Exhibit
                  No. 4.14 of the S-4)

4.22              Executive Stock Agreement and Employment                Incorporated by
                  Agreement with Robert C. Taylor, Jr., dated             reference
                  November 27, 1996 (incorporated by reference to
                  Exhibit No. 4.15 of the S-4)

4.23              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with Brian F. Addy, dated as of             reference
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.11 of the 3rd Quarter 1998 10-Q)

4.24              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with John R. Barnicle, dated as of          refereence
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.12 of the 3rd Quarter 1998 10-Q)

4.25              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with Joseph Beatty, dated as of             reference
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.13 of the 3rd Quarter 1998 10-Q)

4.26              Amendment No. 1 to Executive Employment Agreement       Incorporated by
                  and Consent with Robert C. Taylor, dated as of          reference
                  August 21, 1998 (incorporated by reference to
                  Exhibit No. 4.14 of the 3rd Quarter 1998 10-Q)

4.27              Registration Agreement with Madison Dearborn            Incorporated by
                  Capital Partners, L.P., Frontenac VI, L.P.,             reference
                  Battery Ventures III, L.P., Brian F. Addy, John
                  R. Barnicle, Joseph Beatty, and Robert C. Taylor
                  Jr., dated November 27, 1996 (incorporated by
                  reference to Exhibit No. 4.16 of the S-4)
13
Sequentially
Exhibit Number    Description                                             Numbered Page
--------------    -----------                                             -------------
4.28              Amendment No. 1 to Registration Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty,
                  and Robert C. Taylor Jr., dated as of August 21,
                  1998 (incorporated by reference to Exhibit No.
                  4.15 of the 3rd Quarter 1998 10-Q)

4.29              Amendment No. 4 to Stockholders Agreement with          Incorporated by
                  Madison Dearborn Capital Partners, L.P.,                reference
                  Frontenac VI, L.P., Battery Ventures III, L.P.,
                  Brian F. Addy, John R. Barnicle, Joseph Beatty
                  and Robert C. Taylor, Jr., dated as of May 21,
                  1999 (incorporated by reference to Exhibit No.
                  4.27 of the S-1)

4.30              1998 Equity Plan for Non-Employee Directors             Incorporated by
                  (incorporated by reference to Exhibit No. 10.9 of       reference
                  the 3rd quarter 1998 10-Q)

4.31              Form of Nonqualified Stock Option Agreement for              15
                  use in connection with the 1998 Equity Plan for
                  Non-Employee Directors

4.32              Form of Participation Agreement for use in                   21
                  connection with the 1998 Equity Plan for Non-
                  Employee Directors

5.1               Opinion of Jones, Day, Reavis & Pogue                        23

23.1              Consent of Jones, Day, Reavis & Pogue (included              23
                  in Exhibit 5.1)

23.2              Consent of Independent Public Accountants                    24

24.1              Power of Attorney                                            25
14