<PAGE>

    As filed with the Securities and Exchange Commission on April 3, 2000

                                                     Registration No. 333-____
================================================================================
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
                       VITESSE SEMICONDUCTOR CORPORATION
            (Exact Name of Registrant as Specified in Its Charter)

               Delaware                                     77-0138960
    (State or other jurisdiction of                      (I.R.S. Employer
  incorporation or organization)                       Identification Number)
                                741 Calle Plano
                          Camarillo, California 93012
                                (805) 388-3700
  (Address, including zip code, and telephone number, including area code, of
                   Registrant's principal executive offices)

                         --------------------------------
                        Vitesse International, Inc. 1999
                       International Stock Option Plan
                                    and
                       Vitesse Semiconductor Corporation
                            1991 Stock Option Plan

                         --------------------------------
                               Eugene F. Hovanec
                            Chief Financial Officer
                       Vitesse Semiconductor Corporation
                                741 Calle Plano
                          Camarillo, California 93012
                                (805) 388-3700
(Name, address, including zip code, and telephone number, including area code,
                             of agent for service)

                         --------------------------------
                                  Copies to:
                            FRANCIS S. CURRIE, ESQ.
                             Davis Polk & Wardwell
                              1600 El Camino Real
                         Menlo Park, California 94025
                                (650) 752-2000


<TABLE>
<CAPTION>
                        CALCULATION OF REGISTRATION FEE
====================================================================================================================
          Title of Each Class              Amount to be    Proposed Maximum  Proposed Maximum       Amount of
     of Securities to be Registered         Registered      Offering Price       Aggregate       Registration Fee
                                                              Per  Unit       Offering Price
--------------------------------------------------------------------------------------------------------------------
<S>                                        <C>             <C>               <C>                 <C>
Vitesse International, Inc. 1999
International Stock Option Plan(1)
Common Stock, $0.01 par value                750,000            $93.00(3)       $ 69,750,000(3)    $ 18,414
--------------------------------------------------------------------------------------------------------------------
Vitesse Semiconductor Corporation 1991
Stock Option Plan (2)
Common Stock, $0.01 par value              5,446,182            $93.00(3)       $506,494,926(3)    $133,714.66
--------------------------------------------------------------------------------------------------------------------
Total                                      6,196,182                            $576,244,926       $152,128.66
====================================================================================================================
</TABLE>

(1)  All options outstanding under the Vitesse International, Inc. International
     Stock Option Plan (the "International Options") are exercisable for the
     Registrant's Common Stock.

(2)  All options outstanding under the Vitesse Semiconductor Corporation 1991
     Stock Option Plan (the "Plan") are exercisable for the Registrant's Common
     Stock. Represents additional shares available for award under the Plan as
     of October 1, 1999.

(3)  Estimated in accordance with Rule 457(h) under the Securities Act of 1933,
     as amended, solely for the purpose of calculating the total registration
     fee. Computed based on the closing price of the Company's common stock on
     March 30, 2000.
<PAGE>

                                    PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   Incorporation of Documents by Reference.
          ---------------------------------------

     There are hereby incorporated by reference in this Registration Statement
the following documents and information heretofore filed with the Securities and
Exchange Commission:

     (a)  The Registrant's annual report on Form 10-K for the fiscal year ended
September 30, 1999, filed pursuant to Section 13 of the Securities Exchange Act
of 1934 (the "Exchange Act").

     (b)  The Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
ended December 31, 1999, filed pursuant to Section 13 of the Exchange Act.

     (c)  The Registrant's Current Reports on Form 8-K dated March 6, 2000,
March 13, 2000 and March 27, 2000, filed pursuant to Section 13 of the Exchange
Act.

     (d)  The description of the Registrant's Common Stock to be offered hereby
is contained in the Registrant's Registration Statement on Form S-3 filed with
the Securities and Exchange Commission on October 23, 1996 (File No. 333-14695),
including any amendment or report filed for the purpose of updating such
description.

     All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14
and 15(d) of the Exchange Act subsequent to this Registration Statement, but
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 in this
Registration Statement and to be part hereof from the date of filing such
documents.

Item 4.   Description of Securities.
          -------------------------

     Not applicable.

Item 5.   Interests of Named Experts and Counsel.
          --------------------------------------

     Not applicable.

Item 6.   Indemnification of Directors and Officers.
          -----------------------------------------

     The Registrant has adopted provisions in its Amended and Restated
Certificate of Incorporation which (i) eliminate the personal liability of its
directors to the Registrant and its shareholders for monetary damages arising
from a breach of their fiduciary duties in certain circumstances; and (ii)
authorize the Registrant to indemnify its directors and officers to the fullest
extent permitted by law. The limitation of liability does not affect the
availability of equitable remedies, such as injunctive relief or rescission. In
addition, the Registrant's bylaws provide that the Registrant shall indemnify
its directors and officers to the fullest extent permitted by applicable law.

     The Registrant has entered into separate indemnification agreements with
each of its officers and directors that contain provisions which are in some
respects broader than the specific indemnification provisions contained in the
Delaware General Corporation Law. The indemnification agreements may require the
Registrant, among other things, to indemnify such officers and directors against
certain liabilities that may arise by reason of their status or service as
directors or officers (other than liabilities arising from willful misconduct of
a culpable nature), to advance their expenses incurred as a result of any
proceeding against them as to which they could be indemnified, and to obtain
director's and officer's insurance, if available on reasonable terms.

Item 7.   Exemption from Registration Claimed.
          -----------------------------------

     Not applicable.

                                     II-1
<PAGE>

Item 8.   Exhibits.
          --------

          Exhibit
          Number
          -------
            4.1     Vitesse International, Inc. 1999 International Stock Option
                    Plan filed herewith.

            4.2     Vitesse Semiconductor Corporation 1991 Stock Option Plan
                    incorporated herein by reference to the Registrant's
                    Registration Statement on Form S-1 (File No. 33-43548) filed
                    with the Commission on October 25, 1991.

            5.1     Opinion of Davis Polk & Wardwell (Counsel to the Registrant)
                    as to the legality of securities being registered filed
                    herewith.

           23.1     Consent of KPMG LLP filed herewith.

           23.2     Consent of Davis Polk & Wardwell(contained in Exhibit 5.1).

           24.1     Power of Attorney (see Page II-3).


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 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.

          (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 Section 15(d) of the
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Exchange Act of 1934) 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 of 1933 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 Securities 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
Securities Act and will be governed by the final adjudication of such issue.

                                     II-2
<PAGE>

                                  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 Camarillo, State of California on April 3, 2000.


                                        VITESSE SEMICONDUCTOR
                                        CORPORATION


                                        By: /s/ Eugene F. Hovanec
                                            ------------------------------------
                                            Eugene F. Hovanec
                                            Vice President, Finance and Chief
                                            Financial Officer

                               POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Louis R. Tomasetta and Eugene F. Hovanec, jointly
and severally, his attorneys-in-fact, each with the power of substitution, for
him in any and all capacities, to sign any amendments to this Registration
Statement on Form S-8, and to file the same, with exhibits thereto and other
documents in connection therewith, with the Securities and Exchange Commission,
hereby ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

     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 date indicated.

<TABLE>
<CAPTION>
SIGNATURE                                 DATE                             TITLE
<S>                                       <C>                              <C>
/s/ Louis R. Tomasetta
---------------------------               March 28, 2000                   President, Chief Executive Officer,
Louis R. Tomasetta                                                         and Director (principal executive
                                                                           officer)

/s/ Eugene F. Hovanec
---------------------------               March 28, 2000                   Vice President, Finance and Chief
Eugene F. Hovanec                                                          Financial Officer (principal
                                                                           financial and accounting officer)

/s/ James A. Cole
---------------------------               March 28, 2000                   Director
James A. Cole

/s/ Pierre R. Lamond
---------------------------               March 28, 2000                   Chairman of the Board of Directors
Pierre R. Lamond

/s/ John C. Lewis
---------------------------               March 28, 2000                   Director
John C. Lewis

/s/ Alex Daly
---------------------------               March 28, 2000                   Director
Alex Daly
</TABLE>

                                     II-3
<PAGE>

                       VITESSE SEMICONDUCTOR CORPORATION

                      REGISTRATION STATEMENT ON FORM S-8
                      ----------------------------------


                               INDEX TO EXHIBITS

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

     4.1  Vitesse International, Inc. 1999 International Stock Option Plan filed
          herewith.

     4.2  Vitesse Semiconductor Corporation 1991 Stock Option Plan incorporated
          herein by reference to the Registrant's Registration Statement on Form
          S-1 (File No. 33-43548) filed with the Commission on October 25, 1991.

     5.1  Opinion of Davis Polk & Wardwell (Counsel to the Registrant) as to the
          legality of securities being registered filed herewith.

    23.1  Consent of KPMG LLP filed herewith.

    23.2  Consent of Davis Polk & Wardwell(contained in Exhibit 5.1).

    24.1  Power of Attorney (see Page II-3).

                                     II-4
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 16257}]
{"company-data": {"conformed-name": "VITESSE SEMICONDUCTOR CORP", "cik": "0000880446", "assigned-sic": "3674", "irs-number": "770138960", "state-of-incorporation": "DE", "fiscal-year-end": "0930"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-33918", "film-number": "592594"}, "business-address": {"street1": "741 CALLE PLANO", "city": "CAMARILLO", "state": "CA", "zip": "93012", "phone": "8053883700"}, "mail-address": {"street1": "741 CALLE PLANO", "city": "CAMARILLO", "state": "CA", "zip": "93012"}}
As filed with the Securities and Exchange Commission on April 3, 2000

                                                     Registration No. 333-____
================================================================================
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
                       VITESSE SEMICONDUCTOR CORPORATION
            (Exact Name of Registrant as Specified in Its Charter)

               Delaware                                     77-0138960
    (State or other jurisdiction of                      (I.R.S. Employer
  incorporation or organization)                       Identification Number)
                                741 Calle Plano
                          Camarillo, California 93012
                                (805) 388-3700
  (Address, including zip code, and telephone number, including area code, of
                   Registrant's principal executive offices)

                         --------------------------------
                        Vitesse International, Inc. 1999
                       International Stock Option Plan
                                    and
                       Vitesse Semiconductor Corporation
                            1991 Stock Option Plan

                         --------------------------------
                               Eugene F. Hovanec
                            Chief Financial Officer
                       Vitesse Semiconductor Corporation
                                741 Calle Plano
                          Camarillo, California 93012
                                (805) 388-3700
(Name, address, including zip code, and telephone number, including area code,
                             of agent for service)

                         --------------------------------
                                  Copies to:
                            FRANCIS S. CURRIE, ESQ.
                             Davis Polk & Wardwell
                              1600 El Camino Real
                         Menlo Park, California 94025
                                (650) 752-2000
CALCULATION OF REGISTRATION FEE
====================================================================================================================
          Title of Each Class              Amount to be    Proposed Maximum  Proposed Maximum       Amount of
     of Securities to be Registered         Registered      Offering Price       Aggregate       Registration Fee
                                                              Per  Unit       Offering Price
--------------------------------------------------------------------------------------------------------------------
Vitesse International, Inc. 1999
International Stock Option Plan(1)
Common Stock, $0.01 par value                750,000            $93.00(3)       $ 69,750,000(3)    $ 18,414
--------------------------------------------------------------------------------------------------------------------
Vitesse Semiconductor Corporation 1991
Stock Option Plan (2)
Common Stock, $0.01 par value              5,446,182            $93.00(3)       $506,494,926(3)    $133,714.66
--------------------------------------------------------------------------------------------------------------------
Total                                      6,196,182                            $576,244,926       $152,128.66
====================================================================================================================
(1)  All options outstanding under the Vitesse International, Inc. International
     Stock Option Plan (the "International Options") are exercisable for the
     Registrant's Common Stock.

(2)  All options outstanding under the Vitesse Semiconductor Corporation 1991
     Stock Option Plan (the "Plan") are exercisable for the Registrant's Common
     Stock. Represents additional shares available for award under the Plan as
     of October 1, 1999.

(3)  Estimated in accordance with Rule 457(h) under the Securities Act of 1933,
     as amended, solely for the purpose of calculating the total registration
     fee. Computed based on the closing price of the Company's common stock on
     March 30, 2000.
PART II

              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   Incorporation of Documents by Reference.
          ---------------------------------------

     There are hereby incorporated by reference in this Registration Statement
the following documents and information heretofore filed with the Securities and
Exchange Commission:

     (a)  The Registrant's annual report on Form 10-K for the fiscal year ended
September 30, 1999, filed pursuant to Section 13 of the Securities Exchange Act
of 1934 (the "Exchange Act").

     (b)  The Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
ended December 31, 1999, filed pursuant to Section 13 of the Exchange Act.

     (c)  The Registrant's Current Reports on Form 8-K dated March 6, 2000,
March 13, 2000 and March 27, 2000, filed pursuant to Section 13 of the Exchange
Act.

     (d)  The description of the Registrant's Common Stock to be offered hereby
is contained in the Registrant's Registration Statement on Form S-3 filed with
the Securities and Exchange Commission on October 23, 1996 (File No. 333-14695),
including any amendment or report filed for the purpose of updating such
description.

     All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14
and 15(d) of the Exchange Act subsequent to this Registration Statement, but
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 in this
Registration Statement and to be part hereof from the date of filing such
documents.

Item 4.   Description of Securities.
          -------------------------

     Not applicable.

Item 5.   Interests of Named Experts and Counsel.
          --------------------------------------

     Not applicable.

Item 6.   Indemnification of Directors and Officers.
          -----------------------------------------

     The Registrant has adopted provisions in its Amended and Restated
Certificate of Incorporation which (i) eliminate the personal liability of its
directors to the Registrant and its shareholders for monetary damages arising
from a breach of their fiduciary duties in certain circumstances; and (ii)
authorize the Registrant to indemnify its directors and officers to the fullest
extent permitted by law. The limitation of liability does not affect the
availability of equitable remedies, such as injunctive relief or rescission. In
addition, the Registrant's bylaws provide that the Registrant shall indemnify
its directors and officers to the fullest extent permitted by applicable law.

     The Registrant has entered into separate indemnification agreements with
each of its officers and directors that contain provisions which are in some
respects broader than the specific indemnification provisions contained in the
Delaware General Corporation Law. The indemnification agreements may require the
Registrant, among other things, to indemnify such officers and directors against
certain liabilities that may arise by reason of their status or service as
directors or officers (other than liabilities arising from willful misconduct of
a culpable nature), to advance their expenses incurred as a result of any
proceeding against them as to which they could be indemnified, and to obtain
director's and officer's insurance, if available on reasonable terms.

Item 7.   Exemption from Registration Claimed.
          -----------------------------------

     Not applicable.

                                     II-1
Item 8.   Exhibits.
          --------

          Exhibit
          Number
          -------
            4.1     Vitesse International, Inc. 1999 International Stock Option
                    Plan filed herewith.

            4.2     Vitesse Semiconductor Corporation 1991 Stock Option Plan
                    incorporated herein by reference to the Registrant's
                    Registration Statement on Form S-1 (File No. 33-43548) filed
                    with the Commission on October 25, 1991.

            5.1     Opinion of Davis Polk & Wardwell (Counsel to the Registrant)
                    as to the legality of securities being registered filed
                    herewith.

           23.1     Consent of KPMG LLP filed herewith.

           23.2     Consent of Davis Polk & Wardwell(contained in Exhibit 5.1).

           24.1     Power of Attorney (see Page II-3).

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 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.

          (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 Section 15(d) of the
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Exchange Act of 1934) 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 of 1933 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 Securities 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
Securities Act and will be governed by the final adjudication of such issue.

                                     II-2
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 Camarillo, State of California on April 3, 2000.

                                        VITESSE SEMICONDUCTOR
                                        CORPORATION

                                        By: /s/ Eugene F. Hovanec
                                            ------------------------------------
                                            Eugene F. Hovanec
                                            Vice President, Finance and Chief
                                            Financial Officer

                               POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Louis R. Tomasetta and Eugene F. Hovanec, jointly
and severally, his attorneys-in-fact, each with the power of substitution, for
him in any and all capacities, to sign any amendments to this Registration
Statement on Form S-8, and to file the same, with exhibits thereto and other
documents in connection therewith, with the Securities and Exchange Commission,
hereby ratifying and confirming all that each of said attorneys-in-fact, or his
substitute or substitutes, may do or cause to be done by virtue hereof.

     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 date indicated.
SIGNATURE                                 DATE                             TITLE
/s/ Louis R. Tomasetta
---------------------------               March 28, 2000                   President, Chief Executive Officer,
Louis R. Tomasetta                                                         and Director (principal executive
                                                                           officer)

/s/ Eugene F. Hovanec
---------------------------               March 28, 2000                   Vice President, Finance and Chief
Eugene F. Hovanec                                                          Financial Officer (principal
                                                                           financial and accounting officer)

/s/ James A. Cole
---------------------------               March 28, 2000                   Director
James A. Cole

/s/ Pierre R. Lamond
---------------------------               March 28, 2000                   Chairman of the Board of Directors
Pierre R. Lamond

/s/ John C. Lewis
---------------------------               March 28, 2000                   Director
John C. Lewis

/s/ Alex Daly
---------------------------               March 28, 2000                   Director
Alex Daly
II-3
VITESSE SEMICONDUCTOR CORPORATION

                      REGISTRATION STATEMENT ON FORM S-8
                      ----------------------------------

                               INDEX TO EXHIBITS

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

     4.1  Vitesse International, Inc. 1999 International Stock Option Plan filed
          herewith.

     4.2  Vitesse Semiconductor Corporation 1991 Stock Option Plan incorporated
          herein by reference to the Registrant's Registration Statement on Form
          S-1 (File No. 33-43548) filed with the Commission on October 25, 1991.

     5.1  Opinion of Davis Polk & Wardwell (Counsel to the Registrant) as to the
          legality of securities being registered filed herewith.

    23.1  Consent of KPMG LLP filed herewith.

    23.2  Consent of Davis Polk & Wardwell(contained in Exhibit 5.1).

    24.1  Power of Attorney (see Page II-3).

                                     II-4