<PAGE>   1
    As filed with the Securities and Exchange Commission on December 24, 1997
                                                Registration Statement No. 33-
================================================================================


                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                              --------------------

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

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

                              MEDFORD BANCORP, INC.
             (Exact name of Registrant as specified in its charter)


<TABLE>
<S>                                          <C>                                        <C>
         MASSACHUSETTS                              29 HIGH STREET                          04-3384928
(State or Other Jurisdiction of              MEDFORD, MASSACHUSETTS 02155                (I.R.S. Employer
Incorporation or Organization)                       (617) 395-7700                     Identification No.)
                                     (Address, including zip code, and telephone
                                     number, including area code of Registrant's
                                             principal executive offices)
</TABLE>


                 DEFERRED INVESTMENT PLAN FOR OUTSIDE DIRECTORS
                            (Full title of the Plan)

                                ARTHUR H. MEEHAN
                 Chairman, President and Chief Executive Officer
                              MEDFORD BANCORP, INC.
                                 29 High Street
                          Medford, Massachusetts 02155
                                 (617) 395-7700
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                                    Copy to:
                                PAUL W. LEE, P.C.
                           Goodwin, Procter & Hoar LLP
                                 Exchange Place
                                Boston, MA 02109
                                 (617) 570-1590


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

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
===========================================================================================================================
 TITLE OF SECURITIES TO BE     AMOUNT TO BE          PROPOSED MAXIMUM            PROPOSED MAXIMUM            AMOUNT OF
       REGISTERED(1)           REGISTERED(2)     OFFERING PRICE PER SHARE    AGGREGATE OFFERING PRICE     REGISTRATION FEE
---------------------------------------------------------------------------------------------------------------------------
<S>                            <C>               <C>                         <C>                          <C>
Common Stock, $0.50            100,000 shares        $39.63(3)                  $3,963,000.00              $1,169.09
par value
---------------------------------------------------------------------------------------------------------------------------

(1)  Pursuant to a Shareholder Rights Plan, each share of Common Stock also has
     an associated preferred stock purchase right. In addition, pursuant to
     Rule 416(c) under the Securities Act of 1933, as amended (the "Securities
     Act"), this registration statement also covers an indeterminate amount of
     interests (including any associated preferred stock purchase rights) to be
     offered or sold pursuant to the deferred investment plan for outside
     directors described herein.

(2)  Plus such additional number of shares as may be required pursuant to the
     deferred investment plan for outside directors described herein in the
     event of a stock dividend, reverse stock split, split-up, recapitalization
     or other similar event.

(3)  This estimate is made pursuant to Rule 457(c) and (h) under the Securities
     Act solely for the purpose of determining the amount of the registration
     fee on December 19, 1997, utilizing the average of the high and low sale
     prices reported on the Nasdaq National Market System on that date.

===========================================================================================================================
</TABLE>
This Registration Statement, including exhibits (See Exhibit Index on Page 10),
consists of 19 pages.


<PAGE>   2

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

        The documents containing the information specified in the requirements
of Part I are not required to be filed with the Securities and Exchange
Commission as part of this Registration Statement on Form S-8.


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE.

        Medford Bancorp, Inc. (the "Registrant") hereby incorporates by
reference into this Registration Statement the following documents:

        (a) and (b)   The Registrant's Current Report on Form 8-K as filed with
the Securities and Exchange Commission on November 26, 1997 (the "Form 8-K"),
which includes as exhibits thereto the following: (1) Annual Report of Medford
Savings Bank (the "Bank") on Form F-2 for the year ended December 31, 1996, as
filed with the Federal Deposit Insurance Corporation ("FDIC") (Exhibit 99.1);
Quarterly Report of the Bank on Form F-4 for the quarter ended March 31, 1997,
as filed with the FDIC (Exhibit 99.2); Current Report of the Bank on Form F-3,
as filed with the FDIC on May 7, 1997 (Exhibit 99.3); Quarterly Report of the
Bank on Form F-4 for the quarter ended June 30, 1997, as filed with the FDIC
(Exhibit 99.4); Proxy Statement, dated August 4, 1997, delivered to the Bank's
stockholders in connection with the Bank's September 16, 1997 Special Meeting of
Stockholders, as filed with the FDIC (Exhibit 99.5); Quarterly Report of the
Bank on Form F-4 for the quarter ended September 30, 1997, as filed with the
FDIC (Exhibit 99.6); Current Report of the Bank on Form F-3, as filed with the
FDIC on October 7, 1997 (Exhibit 99.7).

        (c)   The description of the Registrant's common stock, par value $0.50
per share, contained in Exhibit 3.1 and 99.5 to Form 8-K.

        All documents filed by the Registrant or the Plan pursuant to Sections
13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of this
Registration Statement and prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference herein and to be a part hereof from the date of filing of documents.
Any statement contained in a document incorporated or deemed to be incorporated
by reference herein shall be deemed to be modified or superseded for purposes
hereof to the extent that a statement contained herein or in any other
subsequently filed document which also is incorporated or deemed to be
incorporated by reference herein modifies or supersedes such statement. Any such
statement so modified or superseded shall not be deemed, except as so modified
or superseded, 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.



<PAGE>   3




ITEM 6.   INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Indemnification.   The Company is a Massachusetts corporation.
Massachusetts General Laws Chapter 156B, Section 67 provides that a corporation
may, subject to certain limitations, indemnify its directors, officers,
employees and other agents, and persons who serve at its request as directors,
officers, employees or other agents of another organization, or who serve at its
request in any capacity with respect to any employee benefit plan, to the extent
specified or authorized by the corporation's articles of organization, a by-law
adopted by the stockholders, or a vote adopted by the holders of a majority of
the shares of stock entitled to vote on the election of directors.

        Section 67 also provides that a corporation may purchase and maintain
insurance against liability incurred by an officer or director in his capacity
as officer or director, or arising out of his or her status as such, whether or
not the corporation would have the power to indemnify him against such
liability.

        The Company's By-laws provide that directors and officers of the Company
shall, and in the discretion of the Board of Directors, non-officer employees
may, be indemnified by the Company against liabilities and expenses arising out
of service for or on behalf of the Company. The By-laws provide that such
indemnification shall not be provided if it is determined that the action giving
rise to the liability was not taken in good faith in the reasonable belief that
the action was in the best interests of the Company. The By-laws provide that
the indemnification provision in the By-laws does not limit any other right to
indemnification existing independently of the By-laws.

        More specifically, Article VI, Section 1, of the Company's By-laws
provides the following definitions relating to the indemnification of directors
and officers:

               For purposes of this Article: (a) "Officer" means any person who
        serves or has served as a Director of the Company or in any other office
        filled by election or appointment by the stockholders or the Board of
        Directors and any heirs or personal representatives of such person; (b)
        "Non-Officer Employee" means any person who serves or has served as an
        employee of the Company, but who is not or was not an Officer, and any
        heirs or personal representatives of such person; (c) "Proceeding" means
        any action, suit or proceeding, civil or criminal, brought or threatened
        in or before any court, tribunal administrative or legislative body or
        agency and any claim which could be the subject of a Proceeding; and (d)
        "Expenses" means any liability fixed by a judgment, order, decree or
        award in a Proceeding, any amount reasonably paid in settlement of a
        Proceeding and any professional fees or other disbursements reasonably
        incurred in a Proceeding.

        Article VI, Section 2, of the Company's By-laws provides that the
Company shall indemnify Officers as follows:

               Except as provided in Sections 4 and 5 of this Article VI, each
        Officer of the Company shall be indemnified by the Company against all
        Expenses incurred by such Officer in connection with any Proceedings in
        which such Officer is involved as a result of serving or having served
        (a) as an Officer or employee of the Company; (b) as a director, officer
        or employee of any wholly owned subsidiary of the Company; or (c) in any
        capacity with any other corporation, organization, partnership, joint
        venture, trust or other entity at the request or direction of the
        Company.





                                        2

<PAGE>   4



        Article VI, Section 3, of the Company's By-laws provides that the
Company shall indemnify Non-Officer Employees as follows:

               Except as provided in Sections 4 and 5 of this Article VI, each
        Non-Officer Employee of the Company may, in the discretion of the Board
        of Directors, be indemnified against any or all Expenses incurred by
        such Non-Officer Employee in connection with any Proceeding in which
        such Non-Officer Employee is involved as a result of serving or having
        served (a) as a Non-Officer Employee of the Company; (b) as a director,
        officer or employee of any wholly owned subsidiary of the Company; or
        (c) in any capacity with any other corporation, organization,
        partnership, joint venture, trust or other entity at the request or
        direction of the Company.

        Article VI of the Company's By-laws also includes certain provisions
relating to the scope of the indemnification for officers and directors of the
Company and the procedures for determining entitlement to indemnification:

               SECTION 4.    SERVICE AT THE REQUEST OR DIRECTION OF THE COMPANY.
        No indemnification shall be provided to an Officer or Non-Officer
        Employee with respect to serving or having served in any of the
        capacities described in Section 2(c) or 3(c) above unless the following
        two conditions are met: (a) such service was requested or directed in
        each specific case by vote of the Board of Directors prior to the
        occurrence of the event to which the indemnification relates, and (b)
        the Company maintains insurance coverage for the type of indemnification
        sought. In no event shall the Company be liable for indemnification
        under Section 2(c) or 3(c) above for any amount in excess of the
        proceeds of insurance received with respect to such coverage as the
        Company in its discretion may elect to carry. The Company may but shall
        not be required to maintain insurance coverage with respect to
        indemnification under Section 2(c) or 3(c) above. Notwithstanding any
        other provision of this Section 4, but subject to Section 5 of this
        Article VI, the Board of Directors may provide an Officer or Non-Officer
        Employee with indemnification under Section 2(c) or 3(c) above as to a
        specific Proceeding even if one or both of the two conditions specified
        in this Section 4 have not been met and even if the amount of the
        indemnification exceeds the amount of the proceeds of any insurance
        which the Company may have elected to carry, provided that the Board of
        Directors in its discretion determines it to be in the best interests of
        the Company to do so.

               SECTION 5.    GOOD FAITH. No indemnification shall be provided to
        an Officer or to a Non-Officer Employee with respect to a matter as to
        which such person shall have been adjudicated in any Proceeding not to
        have acted in good faith in the reasonable belief that the action of
        such person was in the best interests of the Company. In the event that
        a Proceeding is compromised or settled so as to impose any liability or
        obligation upon an Officer or Non-Officer Employee, no indemnification
        shall be provided to said Officer or Non-Officer Employee with respect
        to a matter if there be a determination that with respect to such matter
        such person did not act in good faith in the reasonable belief that the
        action of such person was in the best interests of the Company. The
        determination shall be made by a majority vote of those Directors who
        are not involved in such Proceeding. However, if more than half of the
        Directors are involved in such Proceeding, the determination shall be
        made by a majority vote of a committee of three disinterested Directors
        chosen by the disinterested Directors at a regular or special meeting.
        If there are fewer than three (3) disinterested Directors, the
        determination shall be based upon the opinion of the Company's regular
        outside counsel.

               SECTION 6.    PRIOR TO FINAL DISPOSITION. Unless otherwise
        provided by the Board of Directors or by the committee pursuant to the
        procedure specified in Section 5 of this Article VI, any indemnification
        provided for under this Article VI shall include payment by the Company
        of Expenses incurred in defending a Proceeding in advance of the final
        disposition of such Proceeding upon receipt




                                        3

<PAGE>   5



        of an undertaking by the Officer or Non-Officer Employee seeking
        indemnification to repay such payment if such Officer or Non-Officer
        Employee shall be adjudicated or determined to be not entitled to
        indemnification under this Article VI.

               SECTION 7.    INSURANCE. The Company may purchase and maintain
        insurance to protect itself and any Officer or Non-Officer Employee
        against any liability of any character asserted against or incurred by
        the Company or any such Officer or Non-Officer Employee, or arising out
        of any such status, whether or not the Company would have the power to
        indemnify such person against such liability by law or under the
        provisions of this Article VI.

               SECTION 8.    OTHER INDEMNIFICATION RIGHTS. Nothing in this 
        Article VI shall limit any lawful rights to indemnification existing
        independently of this Article VI.


ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.

        Not applicable.


ITEM 8.   EXHIBITS.

        The following is a complete list of exhibits filed or incorporated by
reference as part of this Registration Statement.

     *4.1   Specimen certificate for shares of Common Stock of Medford Bancorp,
            Inc.

     *4.2   Articles IV, VI(A), VI(C) and VI(I)-(J) of the Articles of
            Organization of Medford Bancorp, Inc.

     *4.3   Articles II and V of the By-laws of Medford Bancorp, Inc.

      4.4   Deferred Investment Plan for Outside Directors

      4.5   First Amendment to Deferred Investment Plan for Outside Directors

     23.1   Consent of Wolf & Company, P.C., as independent public accountants

     24.1   Power of attorney (see page 7 of this Registration Statement)



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

*   Filed as an exhibit to the Registrant's Current Report on Form 8-K filed
    with the Securities and Exchange Commission on November 26, 1997, and
    incorporated herein by reference thereto.



                                        4

<PAGE>   6



ITEM 9.   UNDERTAKINGS

This Registration Statement on Form S-8 covers securities underlying a deferred
investment plan for outside directors adopted by the Registrant as its plan in
connection with the reorganization of Medford Savings Bank (the "Bank") into
holding company form pursuant to a Plan of Reorganization and Acquisition dated
as of July 29, 1997 between the Registrant and the Bank (the "Plan of
Reorganization"). Pursuant to the Plan of Reorganization, at the effective date
of the Plan of Reorganization, each issued and outstanding share of the Bank's
common stock, par value $0.50 per share (together with associated preferred
stock purchase rights) (except shares held by stockholders exercising
dissenters' rights), automatically and without consideration was converted into
and exchanged for one share of the common stock, par value $0.50 per share of
the Company (together with associated preferred stock purchase rights).
Notwithstanding the foregoing, as required by Item 9 of Form S-8, the Registrant
provides the following 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 of 1933;

                   (ii) To reflect in the prospectus any acts 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 was
        registered) and any deviation from the low or high end of the estimated
        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 a 20% change in the maximum
        aggregate offering price set forth in "Calculation of Registration Fee"
        table in the effective Registration Statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) herein do not apply
if the information required to be included in a post-effective amendment by
those paragraphs is contained in periodic reports filed by the undersigned
Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in the 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;

              (2)  That, for the purpose of determining any liability under the
Securities Act of 1933, 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; and

              (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 of 1933, 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

                                        5

<PAGE>   7



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.

        (h)   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 Securities and Exchange
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.


                                        6

<PAGE>   8



                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, 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 Medford, Commonwealth of Massachusetts, on December
23, 1997.


                             MEDFORD BANCORP, INC.



                             By: /s/ Arthur H. Meehan
                                 -----------------------------------------------
                                 Arthur H. Meehan
                                 Chairman, President and Chief Executive Officer



                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that we, the undersigned officers and
directors of Medford Bancorp, Inc. hereby severally constitute Arthur H. Meehan
and Phillip W. Wong and each of them singly, our true and lawful attorneys with
full power to them, and each of them singly, to sign for us and in our names in
the capacities indicated below, the Registration Statement filed herewith and
any and all amendments to said Registration Statement, and generally to do all
such things in our names and in our capacities as officers and directors to
enable Medford Bancorp, Inc. to comply with the provisions of the Securities Act
of 1933, and all requirements of the Securities and Exchange Commission, hereby
ratifying and confirming our signatures as they may be signed by our said
attorneys, or any of them, to said Registration Statement and any and all
amendments thereto.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
         SIGNATURE                   TITLE                                DATE
         ---------                   -----                                ----
<S>                                  <C>                                  <C> 
/s/ Arthur H. Meehan                 Chairman, President, Chief           December 23, 1997
--------------------------------     Executive Officer and Director 
Arthur H. Meehan                     (principal executive officer)  



/s/ Phillip W. Wong                  Senior Vice President, Treasurer     December 23, 1997
--------------------------------     and Chief Financial Officer 
Phillip W. Wong                      (principal financial and    
                                     accounting officer)         



/s/ Edward D. Brickley               Director                             December 23, 1997
--------------------------------
Edward D. Brickley
</TABLE>









                                        7

<PAGE>   9



<TABLE>
<CAPTION>
         SIGNATURE                   TITLE                                DATE
         ---------                   -----                                ----
<S>                                  <C>                                  <C> 
/s/ David L. Burke                   Director                             December 23, 1997
--------------------------------
David L. Burke



/s/ Paul J. Crowley                  Director                             December 23, 1997
--------------------------------
Paul J. Crowley



/s/ Mary L. Doherty                  Director                             December 23, 1997
--------------------------------
Mary L. Doherty



/s/ Edward J. Gaffey                 Director                             December 23, 1997
--------------------------------
Edward J. Gaffey



/s/ Andrew D. Guthrie Jr., M.D.      Director                             December 23, 1997
--------------------------------
Andrew D. Guthrie Jr., M.D.



--------------------------------     Director                             December __, 1997
Robert A. Havern III



/s/ Arthur H. Meehan                 Director                             December 23, 1997
--------------------------------
Arthur H. Meehan



/s/ Eugene R. Murray                 Director                             December 23, 1997
--------------------------------
Eugene R. Murray



/s/ Francis D. Pizzella              Director                             December 23, 1997
--------------------------------
Francis D. Pizzella
</TABLE>






                                        8

<PAGE>   10



         Pursuant to the requirements of the Securities Act of 1933, the Trustee
of the Deferred Investment Plan for Outside Directors has duly caused this
Registration Statement to be signed by the undersigned, thereunto duly
authorized, in the City of Somerville, Commonwealth of Massachusetts, on
December 23, 1997.


                                               /s/ John J. Sheehan
                                               -----------------------------
                                               John J. Sheehan
                                               Trustee















                                        9

<PAGE>   11



                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
                                                                              SEQUENTIALLY
  EXHIBIT                                                                       NUMBERED
  NUMBER        DESCRIPTION                                                       PAGES
  -------       -----------                                                   ------------
  <S>          <C>                                                            <C>
   *4.1         Specimen certificate for shares of Common
                Stock of Medford Bancorp, Inc.

   *4.2         Articles IV, VI(A), VI(C) and VI(I)-(J) of the Articles of
                Organization of Medford Bancorp, Inc.

   *4.3         Articles II and V of the By-laws of Medford Bancorp, Inc.

    4.4         Deferred Investment Plan for Outside Directors

    4.5         First Amendment to Deferred Investment Plan for Outside
                Directors

   23.1         Consent of Wolf & Company, P.C., as independent
                public accountants

   24.1         Power of attorney (see page 7 of this Registration 
                Statement)
</TABLE>

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

*   Filed as an exhibit to the Registrant's Current Report on Form 8-K filed
    with the Securities and Exchange Commission on November 26, 1997, and
    incorporated herein by reference thereto.










                                       10
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1
    As filed with the Securities and Exchange Commission on December 24, 1997
                                                Registration Statement No. 33-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                              --------------------

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

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

                              MEDFORD BANCORP, INC.
             (Exact name of Registrant as specified in its charter)
MASSACHUSETTS                              29 HIGH STREET                          04-3384928
(State or Other Jurisdiction of              MEDFORD, MASSACHUSETTS 02155                (I.R.S. Employer
Incorporation or Organization)                       (617) 395-7700                     Identification No.)
                                     (Address, including zip code, and telephone
                                     number, including area code of Registrant's
                                             principal executive offices)
DEFERRED INVESTMENT PLAN FOR OUTSIDE DIRECTORS
                            (Full title of the Plan)

                                ARTHUR H. MEEHAN
                 Chairman, President and Chief Executive Officer
                              MEDFORD BANCORP, INC.
                                 29 High Street
                          Medford, Massachusetts 02155
                                 (617) 395-7700
            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

                                    Copy to:
                                PAUL W. LEE, P.C.
                           Goodwin, Procter & Hoar LLP
                                 Exchange Place
                                Boston, MA 02109
                                 (617) 570-1590

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

                         CALCULATION OF REGISTRATION FEE
===========================================================================================================================
 TITLE OF SECURITIES TO BE     AMOUNT TO BE          PROPOSED MAXIMUM            PROPOSED MAXIMUM            AMOUNT OF
       REGISTERED(1)           REGISTERED(2)     OFFERING PRICE PER SHARE    AGGREGATE OFFERING PRICE     REGISTRATION FEE
---------------------------------------------------------------------------------------------------------------------------
Common Stock, $0.50            100,000 shares        $39.63(3)                  $3,963,000.00              $1,169.09
par value
---------------------------------------------------------------------------------------------------------------------------

(1)  Pursuant to a Shareholder Rights Plan, each share of Common Stock also has
     an associated preferred stock purchase right. In addition, pursuant to
     Rule 416(c) under the Securities Act of 1933, as amended (the "Securities
     Act"), this registration statement also covers an indeterminate amount of
     interests (including any associated preferred stock purchase rights) to be
     offered or sold pursuant to the deferred investment plan for outside
     directors described herein.

(2)  Plus such additional number of shares as may be required pursuant to the
     deferred investment plan for outside directors described herein in the
     event of a stock dividend, reverse stock split, split-up, recapitalization
     or other similar event.

(3)  This estimate is made pursuant to Rule 457(c) and (h) under the Securities
     Act solely for the purpose of determining the amount of the registration
     fee on December 19, 1997, utilizing the average of the high and low sale
     prices reported on the Nasdaq National Market System on that date.

===========================================================================================================================
This Registration Statement, including exhibits (See Exhibit Index on Page 10),
consists of 19 pages.
2

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

        The documents containing the information specified in the requirements
of Part I are not required to be filed with the Securities and Exchange
Commission as part of this Registration Statement on Form S-8.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.   INCORPORATION OF DOCUMENTS BY REFERENCE.

        Medford Bancorp, Inc. (the "Registrant") hereby incorporates by
reference into this Registration Statement the following documents:

        (a) and (b)   The Registrant's Current Report on Form 8-K as filed with
the Securities and Exchange Commission on November 26, 1997 (the "Form 8-K"),
which includes as exhibits thereto the following: (1) Annual Report of Medford
Savings Bank (the "Bank") on Form F-2 for the year ended December 31, 1996, as
filed with the Federal Deposit Insurance Corporation ("FDIC") (Exhibit 99.1);
Quarterly Report of the Bank on Form F-4 for the quarter ended March 31, 1997,
as filed with the FDIC (Exhibit 99.2); Current Report of the Bank on Form F-3,
as filed with the FDIC on May 7, 1997 (Exhibit 99.3); Quarterly Report of the
Bank on Form F-4 for the quarter ended June 30, 1997, as filed with the FDIC
(Exhibit 99.4); Proxy Statement, dated August 4, 1997, delivered to the Bank's
stockholders in connection with the Bank's September 16, 1997 Special Meeting of
Stockholders, as filed with the FDIC (Exhibit 99.5); Quarterly Report of the
Bank on Form F-4 for the quarter ended September 30, 1997, as filed with the
FDIC (Exhibit 99.6); Current Report of the Bank on Form F-3, as filed with the
FDIC on October 7, 1997 (Exhibit 99.7).

        (c)   The description of the Registrant's common stock, par value $0.50
per share, contained in Exhibit 3.1 and 99.5 to Form 8-K.

        All documents filed by the Registrant or the Plan pursuant to Sections
13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of this
Registration Statement and prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference herein and to be a part hereof from the date of filing of documents.
Any statement contained in a document incorporated or deemed to be incorporated
by reference herein shall be deemed to be modified or superseded for purposes
hereof to the extent that a statement contained herein or in any other
subsequently filed document which also is incorporated or deemed to be
incorporated by reference herein modifies or supersedes such statement. Any such
statement so modified or superseded shall not be deemed, except as so modified
or superseded, 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.
3

ITEM 6.   INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Indemnification.   The Company is a Massachusetts corporation.
Massachusetts General Laws Chapter 156B, Section 67 provides that a corporation
may, subject to certain limitations, indemnify its directors, officers,
employees and other agents, and persons who serve at its request as directors,
officers, employees or other agents of another organization, or who serve at its
request in any capacity with respect to any employee benefit plan, to the extent
specified or authorized by the corporation's articles of organization, a by-law
adopted by the stockholders, or a vote adopted by the holders of a majority of
the shares of stock entitled to vote on the election of directors.

        Section 67 also provides that a corporation may purchase and maintain
insurance against liability incurred by an officer or director in his capacity
as officer or director, or arising out of his or her status as such, whether or
not the corporation would have the power to indemnify him against such
liability.

        The Company's By-laws provide that directors and officers of the Company
shall, and in the discretion of the Board of Directors, non-officer employees
may, be indemnified by the Company against liabilities and expenses arising out
of service for or on behalf of the Company. The By-laws provide that such
indemnification shall not be provided if it is determined that the action giving
rise to the liability was not taken in good faith in the reasonable belief that
the action was in the best interests of the Company. The By-laws provide that
the indemnification provision in the By-laws does not limit any other right to
indemnification existing independently of the By-laws.

        More specifically, Article VI, Section 1, of the Company's By-laws
provides the following definitions relating to the indemnification of directors
and officers:

               For purposes of this Article: (a) "Officer" means any person who
        serves or has served as a Director of the Company or in any other office
        filled by election or appointment by the stockholders or the Board of
        Directors and any heirs or personal representatives of such person; (b)
        "Non-Officer Employee" means any person who serves or has served as an
        employee of the Company, but who is not or was not an Officer, and any
        heirs or personal representatives of such person; (c) "Proceeding" means
        any action, suit or proceeding, civil or criminal, brought or threatened
        in or before any court, tribunal administrative or legislative body or
        agency and any claim which could be the subject of a Proceeding; and (d)
        "Expenses" means any liability fixed by a judgment, order, decree or
        award in a Proceeding, any amount reasonably paid in settlement of a
        Proceeding and any professional fees or other disbursements reasonably
        incurred in a Proceeding.

        Article VI, Section 2, of the Company's By-laws provides that the
Company shall indemnify Officers as follows:

               Except as provided in Sections 4 and 5 of this Article VI, each
        Officer of the Company shall be indemnified by the Company against all
        Expenses incurred by such Officer in connection with any Proceedings in
        which such Officer is involved as a result of serving or having served
        (a) as an Officer or employee of the Company; (b) as a director, officer
        or employee of any wholly owned subsidiary of the Company; or (c) in any
        capacity with any other corporation, organization, partnership, joint
        venture, trust or other entity at the request or direction of the
        Company.

                                        2
4

        Article VI, Section 3, of the Company's By-laws provides that the
Company shall indemnify Non-Officer Employees as follows:

               Except as provided in Sections 4 and 5 of this Article VI, each
        Non-Officer Employee of the Company may, in the discretion of the Board
        of Directors, be indemnified against any or all Expenses incurred by
        such Non-Officer Employee in connection with any Proceeding in which
        such Non-Officer Employee is involved as a result of serving or having
        served (a) as a Non-Officer Employee of the Company; (b) as a director,
        officer or employee of any wholly owned subsidiary of the Company; or
        (c) in any capacity with any other corporation, organization,
        partnership, joint venture, trust or other entity at the request or
        direction of the Company.

        Article VI of the Company's By-laws also includes certain provisions
relating to the scope of the indemnification for officers and directors of the
Company and the procedures for determining entitlement to indemnification:

               SECTION 4.    SERVICE AT THE REQUEST OR DIRECTION OF THE COMPANY.
        No indemnification shall be provided to an Officer or Non-Officer
        Employee with respect to serving or having served in any of the
        capacities described in Section 2(c) or 3(c) above unless the following
        two conditions are met: (a) such service was requested or directed in
        each specific case by vote of the Board of Directors prior to the
        occurrence of the event to which the indemnification relates, and (b)
        the Company maintains insurance coverage for the type of indemnification
        sought. In no event shall the Company be liable for indemnification
        under Section 2(c) or 3(c) above for any amount in excess of the
        proceeds of insurance received with respect to such coverage as the
        Company in its discretion may elect to carry. The Company may but shall
        not be required to maintain insurance coverage with respect to
        indemnification under Section 2(c) or 3(c) above. Notwithstanding any
        other provision of this Section 4, but subject to Section 5 of this
        Article VI, the Board of Directors may provide an Officer or Non-Officer
        Employee with indemnification under Section 2(c) or 3(c) above as to a
        specific Proceeding even if one or both of the two conditions specified
        in this Section 4 have not been met and even if the amount of the
        indemnification exceeds the amount of the proceeds of any insurance
        which the Company may have elected to carry, provided that the Board of
        Directors in its discretion determines it to be in the best interests of
        the Company to do so.

               SECTION 5.    GOOD FAITH. No indemnification shall be provided to
        an Officer or to a Non-Officer Employee with respect to a matter as to
        which such person shall have been adjudicated in any Proceeding not to
        have acted in good faith in the reasonable belief that the action of
        such person was in the best interests of the Company. In the event that
        a Proceeding is compromised or settled so as to impose any liability or
        obligation upon an Officer or Non-Officer Employee, no indemnification
        shall be provided to said Officer or Non-Officer Employee with respect
        to a matter if there be a determination that with respect to such matter
        such person did not act in good faith in the reasonable belief that the
        action of such person was in the best interests of the Company. The
        determination shall be made by a majority vote of those Directors who
        are not involved in such Proceeding. However, if more than half of the
        Directors are involved in such Proceeding, the determination shall be
        made by a majority vote of a committee of three disinterested Directors
        chosen by the disinterested Directors at a regular or special meeting.
        If there are fewer than three (3) disinterested Directors, the
        determination shall be based upon the opinion of the Company's regular
        outside counsel.

               SECTION 6.    PRIOR TO FINAL DISPOSITION. Unless otherwise
        provided by the Board of Directors or by the committee pursuant to the
        procedure specified in Section 5 of this Article VI, any indemnification
        provided for under this Article VI shall include payment by the Company
        of Expenses incurred in defending a Proceeding in advance of the final
        disposition of such Proceeding upon receipt

                                        3
5

        of an undertaking by the Officer or Non-Officer Employee seeking
        indemnification to repay such payment if such Officer or Non-Officer
        Employee shall be adjudicated or determined to be not entitled to
        indemnification under this Article VI.

               SECTION 7.    INSURANCE. The Company may purchase and maintain
        insurance to protect itself and any Officer or Non-Officer Employee
        against any liability of any character asserted against or incurred by
        the Company or any such Officer or Non-Officer Employee, or arising out
        of any such status, whether or not the Company would have the power to
        indemnify such person against such liability by law or under the
        provisions of this Article VI.

               SECTION 8.    OTHER INDEMNIFICATION RIGHTS. Nothing in this 
        Article VI shall limit any lawful rights to indemnification existing
        independently of this Article VI.

ITEM 7.   EXEMPTION FROM REGISTRATION CLAIMED.

        Not applicable.

ITEM 8.   EXHIBITS.

        The following is a complete list of exhibits filed or incorporated by
reference as part of this Registration Statement.

     *4.1   Specimen certificate for shares of Common Stock of Medford Bancorp,
            Inc.

     *4.2   Articles IV, VI(A), VI(C) and VI(I)-(J) of the Articles of
            Organization of Medford Bancorp, Inc.

     *4.3   Articles II and V of the By-laws of Medford Bancorp, Inc.

      4.4   Deferred Investment Plan for Outside Directors

      4.5   First Amendment to Deferred Investment Plan for Outside Directors

     23.1   Consent of Wolf & Company, P.C., as independent public accountants

     24.1   Power of attorney (see page 7 of this Registration Statement)

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

*   Filed as an exhibit to the Registrant's Current Report on Form 8-K filed
    with the Securities and Exchange Commission on November 26, 1997, and
    incorporated herein by reference thereto.

                                        4
6

ITEM 9.   UNDERTAKINGS

This Registration Statement on Form S-8 covers securities underlying a deferred
investment plan for outside directors adopted by the Registrant as its plan in
connection with the reorganization of Medford Savings Bank (the "Bank") into
holding company form pursuant to a Plan of Reorganization and Acquisition dated
as of July 29, 1997 between the Registrant and the Bank (the "Plan of
Reorganization"). Pursuant to the Plan of Reorganization, at the effective date
of the Plan of Reorganization, each issued and outstanding share of the Bank's
common stock, par value $0.50 per share (together with associated preferred
stock purchase rights) (except shares held by stockholders exercising
dissenters' rights), automatically and without consideration was converted into
and exchanged for one share of the common stock, par value $0.50 per share of
the Company (together with associated preferred stock purchase rights).
Notwithstanding the foregoing, as required by Item 9 of Form S-8, the Registrant
provides the following 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 of 1933;

                   (ii) To reflect in the prospectus any acts 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 was
        registered) and any deviation from the low or high end of the estimated
        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 a 20% change in the maximum
        aggregate offering price set forth in "Calculation of Registration Fee"
        table in the effective Registration Statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) herein do not apply
if the information required to be included in a post-effective amendment by
those paragraphs is contained in periodic reports filed by the undersigned
Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in the 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;

              (2)  That, for the purpose of determining any liability under the
Securities Act of 1933, 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; and

              (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 of 1933, 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

                                        5
7

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.

        (h)   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 Securities and Exchange
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.

                                        6
8

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act of 1933, 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 Medford, Commonwealth of Massachusetts, on December
23, 1997.

                             MEDFORD BANCORP, INC.

                             By: /s/ Arthur H. Meehan
                                 -----------------------------------------------
                                 Arthur H. Meehan
                                 Chairman, President and Chief Executive Officer

                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that we, the undersigned officers and
directors of Medford Bancorp, Inc. hereby severally constitute Arthur H. Meehan
and Phillip W. Wong and each of them singly, our true and lawful attorneys with
full power to them, and each of them singly, to sign for us and in our names in
the capacities indicated below, the Registration Statement filed herewith and
any and all amendments to said Registration Statement, and generally to do all
such things in our names and in our capacities as officers and directors to
enable Medford Bancorp, Inc. to comply with the provisions of the Securities Act
of 1933, and all requirements of the Securities and Exchange Commission, hereby
ratifying and confirming our signatures as they may be signed by our said
attorneys, or any of them, to said Registration Statement and any and all
amendments thereto.

         Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.
SIGNATURE                   TITLE                                DATE
         ---------                   -----                                ----
/s/ Arthur H. Meehan                 Chairman, President, Chief           December 23, 1997
--------------------------------     Executive Officer and Director 
Arthur H. Meehan                     (principal executive officer)  

/s/ Phillip W. Wong                  Senior Vice President, Treasurer     December 23, 1997
--------------------------------     and Chief Financial Officer 
Phillip W. Wong                      (principal financial and    
                                     accounting officer)         

/s/ Edward D. Brickley               Director                             December 23, 1997
--------------------------------
Edward D. Brickley
7
9
SIGNATURE                   TITLE                                DATE
         ---------                   -----                                ----
/s/ David L. Burke                   Director                             December 23, 1997
--------------------------------
David L. Burke

/s/ Paul J. Crowley                  Director                             December 23, 1997
--------------------------------
Paul J. Crowley

/s/ Mary L. Doherty                  Director                             December 23, 1997
--------------------------------
Mary L. Doherty

/s/ Edward J. Gaffey                 Director                             December 23, 1997
--------------------------------
Edward J. Gaffey

/s/ Andrew D. Guthrie Jr., M.D.      Director                             December 23, 1997
--------------------------------
Andrew D. Guthrie Jr., M.D.

--------------------------------     Director                             December __, 1997
Robert A. Havern III

/s/ Arthur H. Meehan                 Director                             December 23, 1997
--------------------------------
Arthur H. Meehan

/s/ Eugene R. Murray                 Director                             December 23, 1997
--------------------------------
Eugene R. Murray

/s/ Francis D. Pizzella              Director                             December 23, 1997
--------------------------------
Francis D. Pizzella
8
10

         Pursuant to the requirements of the Securities Act of 1933, the Trustee
of the Deferred Investment Plan for Outside Directors has duly caused this
Registration Statement to be signed by the undersigned, thereunto duly
authorized, in the City of Somerville, Commonwealth of Massachusetts, on
December 23, 1997.

                                               /s/ John J. Sheehan
                                               -----------------------------
                                               John J. Sheehan
                                               Trustee

                                        9
11

                                  EXHIBIT INDEX
SEQUENTIALLY
  EXHIBIT                                                                       NUMBERED
  NUMBER        DESCRIPTION                                                       PAGES
  -------       -----------                                                   ------------
*4.1         Specimen certificate for shares of Common
                Stock of Medford Bancorp, Inc.

   *4.2         Articles IV, VI(A), VI(C) and VI(I)-(J) of the Articles of
                Organization of Medford Bancorp, Inc.

   *4.3         Articles II and V of the By-laws of Medford Bancorp, Inc.

    4.4         Deferred Investment Plan for Outside Directors

    4.5         First Amendment to Deferred Investment Plan for Outside
                Directors

   23.1         Consent of Wolf & Company, P.C., as independent
                public accountants

   24.1         Power of attorney (see page 7 of this Registration 
                Statement)
---------------------------

*   Filed as an exhibit to the Registrant's Current Report on Form 8-K filed
    with the Securities and Exchange Commission on November 26, 1997, and
    incorporated herein by reference thereto.

                                       10