<PAGE>



             As filed with the Securities and Exchange Commission on
              October 13, 2000 Registration No. 333-______________

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                           SIRIUS SATELLITE RADIO INC.
             (Exact name of registrant as specified in its charter)

             DELAWARE                                 52-170027
  (State or other jurisdiction of                  (IRS Employer
  incorporation or organization)                 Identification No.)

                     1221 AVENUE OF THE AMERICAS, 36TH FLOOR
                               NEW YORK, NY 10020
                                 (212) 584-5100
       (Address, including zip code, and telephone number, including area
               code, of Registrant's principal executive offices)

                 SIRIUS SATELLITE RADIO INC. 401(k) SAVINGS PLAN
                            (Full title of the Plan)

                               PATRICK L. DONNELLY
              SENIOR VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
                           SIRIUS SATELLITE RADIO INC.
                           1221 AVENUE OF THE AMERICAS
                                   36TH FLOOR
                            NEW YORK, NEW YORK 10020
                                 (212) 584-5100

            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

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

                                   Copies to:

                                PAUL D. GINSBERG
                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                           1285 AVENUE OF THE AMERICAS
                          NEW YORK, NEW YORK 10019-6064
                                 (212) 373-3000

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



                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
---------------------------------------------------------------------------------------------------------------------
        TITLE OF EACH CLASS                           PROPOSED MAXIMUM        PROPOSED MAXIMUM
        OF SECURITIES TO BE          AMOUNT TO BE      OFFERING PRICE        AGGREGATE OFFERING         AMOUNT OF
           REGISTERED (1)           REGISTERED (2)      PER SHARE (3)             PRICE(3)           REGISTRATION FEE
---------------------------------------------------------------------------------------------------------------------
<S>                                  <C>                 <C>                    <C>                     <C>
Shares of Sirius Satellite Radio Inc.
Common Stock, par value $0.001
per share (the "Common Stock")

Preferred Stock Purchase Rights(4)      50,000             $48.875              $2,443,750              $645.15

---------------------------------------------------------------------------------------------------------------------
</TABLE>

(1)   In addition, pursuant to Rule 416 under the Securities Act of 1933, as
      amended, this registration statement also covers an indeterminate amount
      of interests to be offered or sold pursuant to the employee benefit plan
      described herein plus any additional shares of Common Stock and Preferred
      Stock Purchase Rights that may be issuable pursuant to the anti-dilution
      provisions of such plan.
(2)   This amount represents a 50,000 share increase in the number shares of the
      Company's Common Stock authorized for issuance under the Sirius Satellite
      Radio Inc. 401(k) Savings Plan.
(3)   The proposed maximum offering price per share and the registration fee
      were calculated in accordance with Rule 457(c) and (h) based on the
      average of the high and low prices for shares of Common Stock on October
      10, 2000, as reported in the Nasdaq National Market System, which was
      $48.875
(4)   Each Preferred Stock Purchase Right (the "Rights") represents the right to
      purchase one one-hundredth of a share of Series B Preferred Stock for each
      share of Common Stock. The Rights are appurtenant to and trade with the
      Common Stock. The value attributable to the Rights, if any, is reflected
      in the value of the Common Stock and the registration fee for the Rights
      is included in the fee for the Common Stock.








<PAGE>





                                  INTRODUCTION

                  This Registration Statement on Form S-8 is filed by Sirius
Satellite Radio Inc., a Delaware corporation (the "Company"), with respect to an
additional 50,000 shares of the Company's common stock, par value of $0.001 per
share, issuable under the Sirius Satellite Radio Inc. 401(k) Savings Plan (the
"Plan"), and consists of those items required by General Instruction E to Form
S-8.

                                     PART II

                 INFORMATION REQUIRED IN REGISTRATION STATEMENT

ITEM 3.           INCORPORATION OF DOCUMENTS BY REFERENCE

                  The following documents filed by the Company with the
Securities and Exchange Commission (the "Commission") are incorporated herein by
reference:

                  1.       The Company's Annual Report on Form 10-K for the year
                           ended December 31, 1999;

                  2.       The Company's Quarterly Reports on Form 10-Q for the
                           quarters ended March 31, 2000 and June 30, 2000; and

                  3.       The Company's Registration Statement on Form S-8
                           (File No. 333-65473) dated October 8, 1998.

                  All other documents filed by the Company with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
of 1934, as amended, subsequent to the date of this registration statement and
prior to the filing of a post-effective amendment which indicates that all
securities registered hereby 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 of such
documents. Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded to
the extent that a statement contained in this registration statement 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 5.           INTERESTS OF NAMED EXPERTS AND COUNSEL

                  Patrick L. Donnelly, Esq., whose legal opinion with respect to
the securities registered hereunder is filed as Exhibit 5.1 hereto, is an
employee of the Company and participates in the Plan and other benefit plans
established by the Company.


ITEM 8.           EXHIBITS

                  See Exhibit Index elsewhere herein.








<PAGE>




                                   SIGNATURES


         Pursuant to the requirements of the Securities Act of 1933, as amended,
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 New York, State of New York, on October 13,
2000.

                                   SIRIUS SATELLITE RADIO INC.



                                   By: /s/ Patrick L. Donnelly
                                       ------------------------------
                                       Patrick L. Donnelly
                                       Senior Vice President,
                                       General Counsel and Secretary







<PAGE>





                                POWER OF ATTORNEY

             KNOW ALL MEN BY THESE PRESENTS, that each individual whose
signature appears below hereby constitutes and appoints Patrick L. Donnelly and
Douglas Kaplan, and each of them, his true and lawful agent, proxy and
attorney-in-fact, each acting alone with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to (i) act on, sign and file with the Commission any and all
amendments (including post-effective amendments) to this registration statement
together with all schedules and exhibits thereto, (ii) act on, sign and file
such certificates, instruments, agreements and other documents as may be
necessary or appropriate in connection therewith, and (iii) take any and all
actions which may be necessary or appropriate in connection therewith, granting
unto such agents, proxies and attorneys-in-fact, and each of them, full power
and authority to do and perform each and every act and thing necessary or
appropriate to be done, as fully for all intents and purposes as he might or
could do in person, hereby approving, ratifying and confirming all that such
agents, proxies and attorneys-in-fact, any of them or any of his or their
substitutes may lawfully do or cause to be done by virtue thereof.

             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>
       Signatures                                 Title                                    Date
       ----------                                 -----                                    ----

<S>                                <C>                                               <C>
 /s/ David Margolese                 Chairman and Chief Executive Officer              October 11, 2000
 ------------------------            (Principal Executive Officer and
 David Margolese                     Principal Financial Officer)

 /s/ Robert D. Briskman              Director                                          October 11, 2000
 ------------------------
 Robert D. Briskman

 /s/ Lawrence F. Gilberti            Director                                          October 11, 2000
 -------------------------
 Lawrence F. Gilberti


 /s/ Joseph V. Vittoria              Director                                          October 11, 2000
 -------------------------
 Joseph V. Vittoria


 /s/ Ralph V. Whitworth              Director                                          October 11, 2000
 -------------------------
 Ralph V. Whitworth


 /s/ Edward Weber, Jr.               Vice President and Controller                     October 11, 2000
 ------------------------            (Principal Accounting Officer)
 Edward Weber, Jr.
</TABLE>










<PAGE>




                                INDEX TO EXHIBITS


<TABLE>
<CAPTION>
EXHIBIT
  NO.
-------
<S>             <C>
5.1             Opinion of Patrick L. Donnelly, Senior Vice President, General Counsel
                and Secretary of the Company (filed herewith).

23.1            Consent of Patrick L. Donnelly, Senior Vice President, General Counsel
                and Secretary of the Company (included in Exhibit 5.1).

23.2            Consent of Arthur Andersen LLP (filed herewith).

24.1            Power of Attorney (included on signature page).
</TABLE>
[{"type": "S-8", "sequence": "1", "filename": "0001.txt", "description": "SIRIUS SATELLITE RADIO INC. S-8", "secsgml_size_bytes": 11795}]
{"company-data": {"conformed-name": "SIRIUS SATELLITE RADIO INC", "cik": "0000908937", "assigned-sic": "4832", "irs-number": "521700207", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-47954", "film-number": "740054"}, "business-address": {"street1": "1221 AVENUE OF THE AMERICAS", "street2": "36TH FLOOR", "city": "NEW YORK", "state": "NY", "zip": "10020", "phone": "2128995000"}, "mail-address": {"street1": "1221 AVENUE OF THE AMERICAS", "street2": "36TH FLOOR", "city": "NEW YORK", "state": "NY", "zip": "10020"}, "former-company": {"former-conformed-name": "CD RADIO INC", "date-changed": "19940203"}}
As filed with the Securities and Exchange Commission on
              October 13, 2000 Registration No. 333-______________

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

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

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

                           SIRIUS SATELLITE RADIO INC.
             (Exact name of registrant as specified in its charter)

             DELAWARE                                 52-170027
  (State or other jurisdiction of                  (IRS Employer
  incorporation or organization)                 Identification No.)

                     1221 AVENUE OF THE AMERICAS, 36TH FLOOR
                               NEW YORK, NY 10020
                                 (212) 584-5100
       (Address, including zip code, and telephone number, including area
               code, of Registrant's principal executive offices)

                 SIRIUS SATELLITE RADIO INC. 401(k) SAVINGS PLAN
                            (Full title of the Plan)

                               PATRICK L. DONNELLY
              SENIOR VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
                           SIRIUS SATELLITE RADIO INC.
                           1221 AVENUE OF THE AMERICAS
                                   36TH FLOOR
                            NEW YORK, NEW YORK 10020
                                 (212) 584-5100

            (Name, address, including zip code, and telephone number,
                   including area code, of agent for service)

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

                                   Copies to:

                                PAUL D. GINSBERG
                    PAUL, WEISS, RIFKIND, WHARTON & GARRISON
                           1285 AVENUE OF THE AMERICAS
                          NEW YORK, NEW YORK 10019-6064
                                 (212) 373-3000

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

                         CALCULATION OF REGISTRATION FEE
---------------------------------------------------------------------------------------------------------------------
        TITLE OF EACH CLASS                           PROPOSED MAXIMUM        PROPOSED MAXIMUM
        OF SECURITIES TO BE          AMOUNT TO BE      OFFERING PRICE        AGGREGATE OFFERING         AMOUNT OF
           REGISTERED (1)           REGISTERED (2)      PER SHARE (3)             PRICE(3)           REGISTRATION FEE
---------------------------------------------------------------------------------------------------------------------
Shares of Sirius Satellite Radio Inc.
Common Stock, par value $0.001
per share (the "Common Stock")

Preferred Stock Purchase Rights(4)      50,000             $48.875              $2,443,750              $645.15

---------------------------------------------------------------------------------------------------------------------
(1)   In addition, pursuant to Rule 416 under the Securities Act of 1933, as
      amended, this registration statement also covers an indeterminate amount
      of interests to be offered or sold pursuant to the employee benefit plan
      described herein plus any additional shares of Common Stock and Preferred
      Stock Purchase Rights that may be issuable pursuant to the anti-dilution
      provisions of such plan.
(2)   This amount represents a 50,000 share increase in the number shares of the
      Company's Common Stock authorized for issuance under the Sirius Satellite
      Radio Inc. 401(k) Savings Plan.
(3)   The proposed maximum offering price per share and the registration fee
      were calculated in accordance with Rule 457(c) and (h) based on the
      average of the high and low prices for shares of Common Stock on October
      10, 2000, as reported in the Nasdaq National Market System, which was
      $48.875
(4)   Each Preferred Stock Purchase Right (the "Rights") represents the right to
      purchase one one-hundredth of a share of Series B Preferred Stock for each
      share of Common Stock. The Rights are appurtenant to and trade with the
      Common Stock. The value attributable to the Rights, if any, is reflected
      in the value of the Common Stock and the registration fee for the Rights
      is included in the fee for the Common Stock.
INTRODUCTION

                  This Registration Statement on Form S-8 is filed by Sirius
Satellite Radio Inc., a Delaware corporation (the "Company"), with respect to an
additional 50,000 shares of the Company's common stock, par value of $0.001 per
share, issuable under the Sirius Satellite Radio Inc. 401(k) Savings Plan (the
"Plan"), and consists of those items required by General Instruction E to Form
S-8.

                                     PART II

                 INFORMATION REQUIRED IN REGISTRATION STATEMENT

ITEM 3.           INCORPORATION OF DOCUMENTS BY REFERENCE

                  The following documents filed by the Company with the
Securities and Exchange Commission (the "Commission") are incorporated herein by
reference:

                  1.       The Company's Annual Report on Form 10-K for the year
                           ended December 31, 1999;

                  2.       The Company's Quarterly Reports on Form 10-Q for the
                           quarters ended March 31, 2000 and June 30, 2000; and

                  3.       The Company's Registration Statement on Form S-8
                           (File No. 333-65473) dated October 8, 1998.

                  All other documents filed by the Company with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
of 1934, as amended, subsequent to the date of this registration statement and
prior to the filing of a post-effective amendment which indicates that all
securities registered hereby 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 of such
documents. Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded to
the extent that a statement contained in this registration statement 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 5.           INTERESTS OF NAMED EXPERTS AND COUNSEL

                  Patrick L. Donnelly, Esq., whose legal opinion with respect to
the securities registered hereunder is filed as Exhibit 5.1 hereto, is an
employee of the Company and participates in the Plan and other benefit plans
established by the Company.

ITEM 8.           EXHIBITS

                  See Exhibit Index elsewhere herein.
SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, as amended,
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 New York, State of New York, on October 13,
2000.

                                   SIRIUS SATELLITE RADIO INC.

                                   By: /s/ Patrick L. Donnelly
                                       ------------------------------
                                       Patrick L. Donnelly
                                       Senior Vice President,
                                       General Counsel and Secretary
POWER OF ATTORNEY

             KNOW ALL MEN BY THESE PRESENTS, that each individual whose
signature appears below hereby constitutes and appoints Patrick L. Donnelly and
Douglas Kaplan, and each of them, his true and lawful agent, proxy and
attorney-in-fact, each acting alone with full power of substitution and
resubstitution, for him and in his name, place and stead, in any and all
capacities, to (i) act on, sign and file with the Commission any and all
amendments (including post-effective amendments) to this registration statement
together with all schedules and exhibits thereto, (ii) act on, sign and file
such certificates, instruments, agreements and other documents as may be
necessary or appropriate in connection therewith, and (iii) take any and all
actions which may be necessary or appropriate in connection therewith, granting
unto such agents, proxies and attorneys-in-fact, and each of them, full power
and authority to do and perform each and every act and thing necessary or
appropriate to be done, as fully for all intents and purposes as he might or
could do in person, hereby approving, ratifying and confirming all that such
agents, proxies and attorneys-in-fact, any of them or any of his or their
substitutes may lawfully do or cause to be done by virtue thereof.

             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:
Signatures                                 Title                                    Date
       ----------                                 -----                                    ----
/s/ David Margolese                 Chairman and Chief Executive Officer              October 11, 2000
 ------------------------            (Principal Executive Officer and
 David Margolese                     Principal Financial Officer)

 /s/ Robert D. Briskman              Director                                          October 11, 2000
 ------------------------
 Robert D. Briskman

 /s/ Lawrence F. Gilberti            Director                                          October 11, 2000
 -------------------------
 Lawrence F. Gilberti

 /s/ Joseph V. Vittoria              Director                                          October 11, 2000
 -------------------------
 Joseph V. Vittoria

 /s/ Ralph V. Whitworth              Director                                          October 11, 2000
 -------------------------
 Ralph V. Whitworth

 /s/ Edward Weber, Jr.               Vice President and Controller                     October 11, 2000
 ------------------------            (Principal Accounting Officer)
 Edward Weber, Jr.
INDEX TO EXHIBITS
EXHIBIT
  NO.
-------
5.1             Opinion of Patrick L. Donnelly, Senior Vice President, General Counsel
                and Secretary of the Company (filed herewith).

23.1            Consent of Patrick L. Donnelly, Senior Vice President, General Counsel
                and Secretary of the Company (included in Exhibit 5.1).

23.2            Consent of Arthur Andersen LLP (filed herewith).

24.1            Power of Attorney (included on signature page).