QuickLinks -- Click here to rapidly navigate through this document

---

---

FORM 6-K
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Report of Foreign Private Issuer
Pursuant to Rule 13a-16 or 15d-16 of
the Securities Exchange Act of 1934
For the month of October 2004

001-14832
(Commission File Number)

---

CELESTICA INC.
(Translation of registrant's name into English)

---

1150 Eglinton Avenue East
Toronto, Ontario
Canada, M3C 1H7
(416) 448-5800
(Address of principal executive offices)

        Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

        Indicate by check mark whether the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):             

        Indicate by check mark whether the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):             

        Indicate by check mark whether by furnishing the information contained in this Form, is the registrant also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

        If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82-                             

---

---

---

Celestica Inc.
Form 6-K
Month of October 2004

The following information filed with this Form 6-K is incorporated by reference in Celestica's registration statements, the prospectuses included therein, and any registration statement subsequently filed by Celestica with the Securities and Exchange Commission:

        •        Confirmation by Computershare Trust Company of Canada of the mailing of Celestica Inc.'s third quarter results to all of Celestica Inc.'s shareholders of record dated October 28, 2004.

Exhibits

99.1 — Confirmation of Mailing

---

SIGNATURES

        Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

		CELESTICA INC.
Date: October 29, 2004
		By:	/s/  ELIZABETH L. DELBIANCO       Elizabeth L. DelBianco Chief Legal Officer

---

EXHIBIT INDEX

99.1    —        Confirmation of Mailing

---

QuickLinks

Celestica Inc. Form 6-K Month of October 2004
SIGNATURES
EXHIBIT INDEX

				Investor Services
		Computershare Trust Company of Canada 100 University Avenue Toronto, Ontario M5J 2Y1 Telephone 1-800-663-9097 www.computershare.com
				Canada Australia Channel Islands Hong Kong Germany Ireland New Zealand Philippines South Africa United Kingdom USA

October 29, 2004

Celestica Inc.
1150 Eglinton Avenue East
Toronto, Ontario
M3C 1H7

Dear Sirs:

Subject: Celestica Inc. (the "Corporation")

We confirm that the following English material was sent by pre-paid mail on October 28, 2004 to shareholders whose names appear on the Corporation's Supplemental Mailing List in compliance with current securities legislation requirements.

1.

Third Quarter Financial Results ended September 30, 2004

In compliance with regulations made under the Securities Act, we are providing this material to you in our capacity as agent for the Corporation.

Yours truly,

(Signed)
Mariano Salvador
Assistant Account Manager
Client Services
(416) 263-9529 Tel
(416) 981-9800 Fax

---