天弘科技美股招股说明书(2026-08-05版)

This preliminary prospectus supplement relates to an effective registration statement filed with the U.S. Securities and ExchangeCommission, but is not complete and may be changed. This preliminary prospectus supplement and the accompanying prospectus arenot an offer to sell the securities described herein, and are not soliciting an offer to buy such securities, in any state or jurisdictionwhere such offer or sale is not permitted. Filed Pursuant to Rule424(b)(5)Registration No.333-285515 PRELIMINARY PROSPECTUS SUPPLEMENT(To Prospectus dated March3, 2025) $3,000,000,000 Celestica Inc. Common Shares We are offeringof our common shares, without par value (“Common Shares”), pursuant to this prospectus supplement andthe accompanying prospectus. Our Common Shares are listed on the New York Stock Exchange (the “NYSE”) and the Toronto StockExchange (the “TSX”) under the symbol “CLS.” On August 4, 2026, the closing prices of our Common Shares on the NYSE and theTSX were $371.15 and C$523.74, respectively. See “Risk Factors” beginning on pageS-11 of this prospectus supplement and in our Annual Report on Form10-K for thefiscal year ended December31, 2025 and our Quarterly Report on Form10-Q for the fiscal quarter ended June30, 2026 for adiscussion of certain risks that should be considered in connection with an investment in our Common Shares. Neither the Securities and Exchange Commission (the “SEC”) nor any state or Canadian securities commission has approvedor disapproved of our Common Shares or determined that this prospectus supplement or the accompanying prospectus isaccurate or complete. Any representation to the contrary is a criminal offense. Purchasers of the Common Shares should be aware that the acquisition of such Common Shares may have tax consequencesboth in the United States and in Canada. This prospectus supplement may not describe these tax consequences fully. See“Material U.S. Federal Income Tax Considerations” and “Material Canadian Federal Income Tax Considerations.” The enforcement by investors of civil liabilities under U.S. federal securities laws may be affected adversely by the fact that we areincorporated under the laws of the Province of Ontario, Canada, that certain of our officers are residents of Canada, and that significantportion of our assets and the assets of these persons are located outside the United States. See “Enforceability of Civil Liabilities.” We have granted the Underwriters an option to purchase up to an additionalCommon Shares from us at the public offeringprice less the underwriting discounts and commissions, exercisable for 30 days from the date of this prospectus supplement, to coverover-allotments, if any. We have applied to list the Common Shares distributed under this prospectus supplement on the NYSE and the TSX. Listing will besubject to us fulfilling all of the listing requirements of the NYSE and of the TSX, respectively. We urge you to carefully read this prospectus supplement and the accompanying prospectus, which describe the terms of this offering,before you make your investment decision. The Underwriters expect to deliver the Common Shares to purchasers on or about, 2026. Citigroup* BofA Securities* * in alphabetical order The date of this prospectus supplement is, 2026. We are responsible for the information contained and incorporated by reference in this prospectus supplement, theaccompanying prospectus and in any related free writing prospectus we prepare or authorize. No person is authorized to giveany information or to make any representation that is different from, or in addition to, those contained or incorporated byreference into this prospectus supplement, the accompanying prospectus or any related free writing prospectus that weprepare or authorize. If given or made, such information or representations must not be relied upon as having been authorizedby us, and we take no responsibility for any information that others may give you. If you are in a jurisdiction where offers tosell, or solicitations of offers to purchase, the Common Shares offered by this document are unlawful, or if you are a person towhom it is unlawful to direct these types of activities, then the offer presented in this document does not extend to you. Theinformation contained in this document speaks only as of the date of this document, unless the information specificallyindicates that another date applies. You should not assume that the information contained in or incorporated by reference inthis prospectus supplement, the accompanying prospectus or in any such free writing prospectus is accurate as of any dateother than the date of the document containing the information. This prospectus supplement, the accompanying prospectusand any free writing prospectus prepared by us and/or on our behalf by the Underwriters do not constitute an offer to sell orthe solicitation of an offer to buy any securities other than the securities described in this prospectus su