QuickLinks -- Click here to rapidly navigate through this document

---

---

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16 of
the Securities Exchange Act of 1934

For the month of January 2005

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 January 2005

        The following information filed with this Form 6-K shall not be deemed to be incorporated by reference into any filing under the Securities Act of 1933, except as shall be expressly set forth by specific reference in such filing:

•

Celestica Inc.'s letter to holders of Subordinate Voting Shares of Celestica Inc., dated January 18, 2004.



•

Celestica Inc.'s letter to holders of Subordinate Voting Shares of Celestica Inc. under the Celestica Employee Share Ownership Plan, dated January 18, 2004.

Exhibits

99.1		—		Letter to Holders of Subordinate Voting Shares
99.2		—		Letter to Holders of Subordinate Voting Shares under the Celestica Employee Share Ownership Plan

---

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: January 24, 2005
		By:	/s/  ELIZABETH L. DELBIANCO       Elizabeth L. DelBianco Chief Legal Officer

---

EXHIBIT INDEX

99.1		—		Letter to Holders of Subordinate Voting Shares
99.2		—		Letter to Holders of Subordinate Voting Shares under the Celestica Employee Share Ownership Plan

---

QuickLinks

CELESTICA INC. FORM 6–K – Month of January 2005
SIGNATURES
EXHIBIT INDEX

Exhibit 99.1

								9th Floor, 100 University Avenue Toronto, Ontario M5J 2Y1 www.computershare.com		+
						000001
		Mr A Sample         Designation (if any)         Add1         Add2         add3         add4         add5         add6						Holder Account Number C1234567890              X X X
		Use a black or blue pen. Print in CAPITAL letters inside the box as shown in this example.		ý

---

Do you want to receive Celestica Inc.'s Annual Report?

---

Dear Shareholder,

Annually and in accordance with securities regulations, Celestica sends you its annual financial statements and related Management's Discussion & Analysis ("Annual Report"). You can now advise us in writing that you do not want to receive a copy of the Annual Report through the mail.

If you DO NOT want to receive the Annual Report by mail, simply check the box below and send this letter in the enclosed return envelope provided.

o    NO, I/we DO NOT want to receive the Annual Report.

Celestica is committed to reducing costs to benefit all shareholders and preserving the environment. Rather than receiving the Annual Report by mail, registered shareholders may elect to receive it by registering online at www.computershare.com. Click "Investors" and then "Electronic Shareholder Communications". You will be required to provide your Holder Account Number, please see upper right-hand side of this form.

Privacy Notice

Computershare is committed to protecting your personal information. In the course of providing services to you and our corporate clients, we receive non-public personal information about you — from transactions we perform for you, forms you send us, other communications we have with you or your representatives, etc. This information could include your name, address, social insurance number, securities holdings and other financial information. We use this to administer your account, to better serve your and our clients' needs and for other lawful purposes relating to our services. We have prepared a Privacy Code to tell you more about our information practices and how your privacy is protected. It is available at our website, computershare.com, or by writing us at 100 University Avenue, Toronto, Ontario, M5J 2Y1.

o    C L S Q		1 E R E G I			+
006D8C				CPUQC01.E.INT/000001/i1234

---

Exhibit 99.2

								9th Floor, 100 University Avenue Toronto, Ontario M5J 2Y1 www.computershare.com		+
						000001
		Mr A Sample         Designation (if any)         Add1         Add2         add3         add4         add5         add6
								01234567890
		Use a black or blue pen. Print in CAPITAL letters inside the box as shown in this example.		ý

---

Do you want to receive Celestica Inc.'s Annual Report?

---

Dear Shareholder,

Celestica is pleased to offer you a new registration option for receipt of our Annual Report. New securities regulations provide that a company is required to send its Annual Report only to those non-registered owners of securities who specifically request it.

Accordingly, if you want to receive the Annual Report, please register either:

1.

By Email — Online at www.computershare.com/ca/mailinglist; or

2.

By mail — Mark the box below if you wish to receive the Company's Annual Report by mail. Then return this form in the enclosed return envelope.

o    YES, I/we DO want to receive the Annual Report.

If you choose not to receive the Annual Report, it will be available to you online at the same time that it is mailed to shareholders at: www.celestica.com/investor

This form is being sent to non-registered owners of securities. The Company or its agent has sent this form directly to you. Your name and address and information about your securities have been obtained in accordance with applicable securities regulatory requirements from the intermediary holding on your behalf.

Privacy Notice

Computershare is committed to protecting your personal information. In the course of providing services to you and our corporate clients, we receive non-public personal information about you — from transactions we perform for you, forms you send us, other communications we have with you or your representatives, etc. This information could include your name, address, social insurance number, securities holdings and other financial information. We use this to administer your account, to better serve your and our clients' needs and for other lawful purposes relating to our services. We have prepared a Privacy Code to tell you more about our information practices and how your privacy is protected. It is available at our website, computershare.com, or by writing us at 100 University Avenue, Toronto, Ontario, M5J 2Y1.

o    Y 0 5 Q _ P 5 4		2 E B E N E			+
006D7C				CPUQC01.E.INT/000001/i1234

---