Exhibit 99.3

BROKER ADDRESS 123 ANY STREET ANY CITY/PROVINCE A1A 1A1 JOHN A. SAMPLE 123 ANY STREET ANYCITY PR A1A 1A1 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX BROKER LOGO 1 OF 2 S91970−81 010 E: C S:3 E:2 1/1 M A:A V: 1 PLEASE SEE OVER B-05022021 About Voting A meeting is being held for the holders of the securities listed on the other side of this form. As a beneficial holder of the securities you have the right to vote on the item(s) being covered at the meeting, which are described in the Proxy Statement. The control number has been assigned to you to identify your shares for voting. You must keep your control number confidential and not disclose it to others other than when you vote using one of the voting options set out on this form. Should you send this form or provide your control number to others, you are responsible for any subsequent voting of, or subsequent inability to vote, your shares. Please read the Proxy Statement carefully and take note of any relevant proxy deposit date. We need to receive your voting instructions at least one business day before the proxy deposit date noted on the reverse. If you have any questions, please contact the person who services your account. We have been requested to forward to you the enclosed proxy material relative to securities held by us in your account but not registered in your name. Only we as the holder of record can vote such securities. We shall be pleased to vote your securities in accordance with your wishes, if you will execute the form and return it to us promptly in the enclosed business reply envelope. It is understood that if you sign without otherwise marking the form your securities will be voted as recommended in the Proxy Statement. For this meeting, the extent of our authority to vote your securities in the absence of your instructions can be determined by referring to the applicable voting instruction number indicated on the face of your form. For margin accounts, in the event your securities have been loaned over record date, the number of securities we vote on your behalf has been or can be adjusted downward. Please note that under a rule amendment adopted by the New York Stock Exchange for shareholder meetings held on or after January 1, 2010, brokers are no longer allowed to vote securities held in their clients’ accounts on uncontested elections of directors unless the client has provided voting instructions (it will continue to be the case that brokers cannot vote their clients’ securities in contested director elections). Consequently, if you want us to vote your securities on your behalf on the election of directors, you must provide voting instructions to us. Voting on matters presented at shareholder meetings, particularly the election of directors is the primary method for shareholders to influence the direction taken by a publicly-traded company. We urge you to participate in the election by returning the enclosed voting instruction form to us with instructions as to how to vote your securities in this election. If your securities are held by a broker who is a member of the New York Stock Exchange (NYSE), the rules of the NYSE will guide the voting procedures. These rules provide that if instructions are not received from you prior to the issuance of the first vote, the proxy may be given at the discretion of your broker (on the tenth day, if the material was mailed at least 15 days prior to the meeting date or on the fifteenth day, if the proxy material was mailed 25 days or more prior to the meeting date). In order for your broker to exercise this discretionary authority, proxy material would need to have been mailed at least 15 days prior to the meeting date, and one or more of the matters before the meeting must be deemed “routine” in nature according to NYSE guidelines. If these two requirements are met and you have not communicated to us prior to the first vote being issued, we may vote your securities at our discretion on any matters deemed to be routine. We will nevertheless follow your instructions, even if our discretionary vote has already been given, provided your instructions are received prior to the meeting date. The following instructions provide specifics regarding the meeting for which this voting form applies. Instruction 1 All proposals for this meeting are considered “routine”. We may vote in our discretion on all proposals, if your instructions are not received. If your securities are held by a bank, your securities cannot be voted without your specific instructions. Instruction 2 In order for your securities to be represented at the meeting on one or more matters before the meeting, it will be necessary for us to have your specific voting instructions. If your securities are held by a bank, your securities cannot be voted without your specific instructions. Instruction 3 In order for your securities to be represented at the meeting, it will be necessary for us to have your specific voting instructions. Instruction 4 We have previously sent you proxy soliciting material pertaining to the meeting of shareholders of the company indicated. According to our latest records, we have not as of yet received your voting instruction on the matter(s) to be considered at this meeting and the company has requested us to communicate with you in an endeavor to have your securities voted. **If you hold your securities through a Canadian broker or bank, please be advised that you are receiving the voting instruction form and meeting materials, at the direction of the issuer. Even if you have declined to receive securityholder materials, a reporting issuer is required to deliver these materials to you. If you have advised your intermediary that you object to the disclosure of your beneficial ownership information to the reporting issuer, it is our responsibility to deliver these materials to you on behalf of the reporting issuer. These materials are being sent at no cost to you. To attend the meeting and vote your shares in person or virtually (as applicable) If you wish to attend the meeting, mark the appropriate box on the other side of this form, and a legal proxy will be issued and mailed to you. The legal proxy will grant you or your designate the right to attend the meeting and vote in person or virtually (as applicable), subject to any rules described in the Proxy Statement applicable to the delivery of a proxy. The legal proxy will be mailed to the name and address of the beneficial holder noted above. You need to submit and deliver the legal proxy in accordance with the proxy deposit date and any instructions or disclosures noted in the Proxy Statement. You or your des-ignate must attend the meeting for your vote to be counted. Allow sufficient time for the mailing and return of the legal proxy by the proxy deposit date to the issuer or its agent. Please be advised that if you, the beneficial holder, ask for a legal proxy to be issued, you may have to take additional steps in order for the proxy to be fully effective under applicable law. For example, it may be necessary that you deposit the legal proxy with the issuer or its agent in advance of the meeting. Further, if a legal proxy is issued, all other voting instructions given on this voting instruction form will not be effective. This Voting Instruction Form confers discretionary authority to vote on such other business as may properly come before the meeting or any adjournment thereof. Disclosure of Information – Electing to Receive Financial Statements or Requesting Meeting Materials By electing to receive the financial statements or requesting meeting materials, your name and address may be provided to the issuer (or its agent) for mailing purposes. Thursday, April 25, 2024 at 9:30 am EDT Celestica Inc.’s headquarters at 5140 Yonge Street, Suite 1900 Toronto, Ontario and online at https://meetnow.global/MUGXJDC Annual and Special Meeting Celestica Inc. WHEN: WHERE: VOTING INSTRUCTION FORM

VOTING INSTRUCTION FORM STEP 2 COMPLETE YOUR VOTING DIRECTIONS A/C RECORD DATE: PROXY DEPOSIT DATE: MEETING DATE: MEETING TYPE: STEP 1 REVIEW YOUR VOTING OPTIONS BY TELEPHONE: YOU MAY ENTER YOUR VOTING INSTRUCTIONS BY TELEPHONE AT: BY MAIL: THIS VOTING INSTRUCTION FORM MAY BE RETURNED BY MAIL IN THE ENVELOPE PROVIDED. REMINDER: PLEASE REVIEW THE INFORMATION / PROXY CIRCULAR BEFORE VOTING. SEE VOTING INSTRUCTION NO. 2 ON REVERSE ONLINE: VOTE AT PROXYVOTE.COM USING YOUR COMPUTER OR MOBILE DATA DEVICE. ***WE NEED TO RECEIVE YOUR VOTING INSTRUCTIONS AT LEAST ONE BUSINESS DAY BEFORE THE PROXY DEPOSIT DATE.*** SCAN TO VIEW MATERIAL AND VOTE NOW ➔ FOR WITHHOLD FOR FOR AGAINST STEP 3 THIS DOCUMENT MUST BE SIGNED AND DATED SIGNATURE(S) *INVALID IF NOT SIGNED* MMD D Y Y 0-R3 ANNUAL INTERIM VOTING RECOMMENDATION: FOR ALL THE NOMINEES PROPOSED AS DIRECTORS (FILL IN ONLY ONE BOX “ “ PER NOMINEE IN BLACK OR BLUE INK) VOTING RECOMMENDATIONS ARE INDICATED BY OVER THE BOXES (FILL IN ONLY ONE BOX “ ” PER ITEM IN BLACK OR BLUE INK) FOR AGAINST FILL IN THE BOX “ “ TO THE RIGHT IF YOU PLAN TO ATTEND THE MEETING AND VOTE THESE SHARES IN PERSON. AGAINST March 8, 2024 April 23, 2024 Thursday, April 25, 2024 at 9:30 am EDT Annual and Special Meeting Celestica Inc. *NOTE* To participate and vote at the Meeting (in person or virtually), U.S. resident non-registered shareholders MUST first obtain a valid legal proxy from their intermediary, and then register themselves or their Appointee in advance of the Meeting. After first obtaining a valid legal proxy, U.S. resident non-registered shareholders MUST submit a copy of their legal proxy to Computershare. Refer to the Notice of Availability of Meeting Materials accompanying this voting instruction form to access the Proxy Statement for details. *NOTE* Under securities regulation and Notice-and-Access procedures, shareholders are being directed to view the meeting-related materials online. Refer to the Notice of Availability of Meeting Materials accompanying this voting instruction form for details. *NOTE* Fill in the box to the right above STEP 3 if you plan to attend the Meeting and vote your shares in person or virtually. 01 ELECTION OF DIRECTORS: 02 Robert A. Cascella 03 Deepak Chopra 04 Françoise Colpron 05 Jill Kale 06 Laurette T. Koellner 08 Luis A. Müller 09 Michael M. Wilson 01 Kulvinder (Kelly) Ahuja 07 Robert A. Mionis FOR WITHHOLD FOR WITHHOLD 02 Appointment of KPMG LLP as auditor of Celestica Inc. Authorization of the Board of Directors of Celestica Inc. to fix the remuneration of the auditor. 03 04 Advisory resolution on Celestica Inc.’s approach to executive compensation. 05 Approval of articles of amendment of Celestica Inc. 06 Confirmation of Celestica Inc.’s amended and restated By-Law 1. ITEM(S HIGHLIGHTED TEXT FOR AGAINST To receive Annual and/or Interim Financial Statements and accompanying Management's Discussion and Analysis, please mark the applicable box. To receive future meeting materials by mail check the box to the right. To request materials for this meeting refer to the notice included in the package with this form.