MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT Dear Stockholders of Kansas City Southern: On May 21, 2021, Kansas City Southern (which we refer to as “KCS”), Canadian National Railway Company (which we refer to as “CN”) and Brooklyn Merger Sub, Inc., a wholly owned subsidiary of CN (which we refer to as “merger sub”), entered into an Agreement and Plan of Merger (which, as it may be amended from time to time, we refer to as the “merger agreement”) that provides for the acquisition of KCS by CN. On the terms and subject to the conditions set forth in the merger agreement, merger sub will merge with and into KCS (which we refer to as the “merger”), with KCS surviving the merger as a wholly owned subsidiary of CN. At the effective time of the merger (which we refer to as the “effective time”), each share of common stock, par value $0.01 per share, of KCS (which we refer to as “KCS common stock”) issued and outstanding immediately prior to the effective time (other than certain excluded shares as described in the merger agreement) that you own will be converted into the right to receive (i) 1.129 (which number we refer to as the “exchange ratio”) CN common shares (which we refer to as the “CN common shares”) and (ii) $200.00 in cash, without interest (which we refer to, collectively, as the “merger consideration”), and each share of 4% noncumulative preferred stock of KCS, par value $25.00 (which we refer to as the “KCS preferred stock” and, together with the KCS common stock, the “KCS voting stock”), issued and outstanding immediately prior to the effective time (other than certain excluded shares as described in the merger agreement) that you own will be converted into the right to receive $37.50 per share in cash, without interest (which we refer to as the “preferred merger consideration”). The exchange ratio is fixed and will not be adjusted to reflect changes in the price of KCS common stock or CN common shares prior to the effective time. The CN common shares issued in connection with the transaction will be listed on the New York Stock Exchange (which we refer to as the “NYSE”) and the Toronto Stock Exchange (which we refer to as the “TSX”). Based on the number of shares of KCS common stock and CN common shares outstanding on July 1, 2021, upon completion of the transaction, we expect that former holders of KCS common stock and KCS preferred stock (who we collectively refer to as “KCS stockholders”) would own approximately 12.65% of the outstanding CN common shares immediately after the merger, and persons who were CN shareholders immediately prior to the merger would own approximately 87.35% of the outstanding CN common shares. CN common shares are traded on the NYSE and the TSX under the symbols “CNI” and “CNR”, respectively. KCS common stock and KCS preferred stock are traded on the NYSE under the symbols “KSU” and “KSU-P,” respectively. We encourage you to obtain current quotes for the KCS common stock and CN common shares. Because the exchange ratio is fixed, the market value of the merger consideration to holders of KCS common stock will fluctuate with the market price of the CN common shares and will not be known at the time that KCS stockholders vote on the transaction. Based on the closing price of CN common shares of $106.39 on the NYSE on May 20, 2021, the last full trading day before the public announcement of the merger agreement, the implied value of the merger consideration to holders of KCS common stock was approximately $320.11 per share of KCS common stock, based on the 1.129 exchange ratio. On July 1, 2021, the latest practicable trading day before the date of this proxy statement/prospectus, the closing price of CN common shares on the NYSE was $105.62 per share, resulting in an implied value of the merger consideration to holders of KCS common stock of $319.24 per share of KCS common stock. At the special meeting of KCS’s stockholders to be held on August 19, 2021 (which we refer to as the “KCS special meeting”), KCS stockholders will be asked to consider and vote on (1) a proposal to adopt the merger agreement (which we refer to as the “KCS merger proposal”), (2) a proposal to approve, on a non-binding advisory basis, the compensation that may be paid or become payable to KCS’s named executive officers that is based on or otherwise relates to the transactions contemplated by the merger agreement and (3) a proposal to adjourn the KCS special meeting if there are insufficient votes to approve the KCS merger proposal or to ensure that any supplement or amendment to this proxy statement/prospectus is timely provided to KCS stockholders (which we collectively refer to as the “KCS proposals”). The board of directors of KCS (which we refer to as the “KCS board”) unanimously recommends that KCS stockholders vote “FOR” each of the KCS proposals at the KCS special meeting. We cannot complete the transaction unless the KCS merger proposal is approved by KCS stockholders. Your vote is very important, regardless of the number of shares you own. Whether or not you plan to attend the KCS special meeting, please promptly mark, sign and date the accompanying proxy card and return it in the enclosed postage-paid envelope or call the toll-free telephone number or use the internet as described in the instructions included with your proxy card in order to authorize the individuals named on your proxy card to vote your shares at the KCS special meeting. This proxy statement/prospectus provides you with important information about the KCS special meeting, the transaction and each of the KCS proposals. We encourage you to read the entire document carefully, in particular the “Risk Factors” section on page 20 for a discussion of risks relevant to the transaction. We look forward to the successful completion of the transaction. As noted above, the KCS board unanimously recommends that KCS stockholders vote “FOR” the KCS merger proposal and each of the other KCS proposals. Sincerely, Patrick J. Ottensmeyer President and Chief Executive Officer Kansas City Southern NEITHER THE U.S. SECURITIES AND EXCHANGE COMMISSION NOR ANY U.S. STATE OR CANADIAN PROVINCIAL OR TERRITORIAL SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THE SECURITIES TO BE ISSUED IN CONNECTION WITH THE TRANSACTION OR DETERMINED IF THIS PROXY STATEMENT/PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE. The date of this proxy statement/prospectus is July 7, 2021, and it is first being mailed to KCS stockholders on or about July 7, 2021. ADDITIONAL INFORMATION KCS and CN file periodic and other reports and information with the U.S. Securities and Exchange Commission (which we also refer to as the “SEC”). This proxy statement/prospectus incorporates by reference important business and financial information about KCS and CN from documents that are not included in or delivered with this proxy statement/prospectus. For a listing of the documents incorporated by reference into this proxy statement/prospectus, see the section entitled “Where You Can Find Additional Information” on page 205. You can obtain copies of the documents incorporated by reference into this proxy statement/prospectus, without charge, from the SEC’s website at www.sec.gov or on the Canadian System for Electronic Document Analysis and Retrieval (which we refer to as “SEDAR”), the Canadian equivalent of the SEC’s system, at www.sedar.com. You may also obtain copies of documents filed by KCS with the SEC from KCS’s website at www.investors.kcsouthern.com under the tab “Financial Information” and then under the headings “Annual Reports & Proxy Statements” and “SEC Filings”, and copies of documents filed by CN with the SEC and SEDAR from CN’s website at www.cn.ca/en/investors/ under the tab “Financial Results” and then under the heading “Regulatory Filings.” We are not incorporating the contents of the websites of the SEC, KCS, CN or any other entity or any other website into this proxy statement/prospectus. We are providing the information about how you can obtain certain documents that are incorporated by reference into this proxy statement/prospectus at these websites only for your convenience. You can also request copies of such documents incorporated by reference into this proxy statement/prospectus (excluding all exhibits, unless an exhibit has specifically been incorporated by reference into this proxy statement/prospectus), without charge, by requesting them in writing or by telephone from the appropriate company at the following addresses and telephone numbers: Kansas City Southern Canadian National Railway Company 427 West 12th Street 935 de La Gauchetière Street Kansas City, Missouri 64105 West Montreal, Quebec, Canada H3B 2M9 Attention: Corporate Secretary Attention: Corporate Secretary Telephone: 1-888-800-3690 Telephone: 1-888-888-5909 In addition, if you have questions about the transaction or the KCS special meeting, need additional copies of this proxy statement/prospectus or need to obtain proxy cards or other information related to the proxy solicitation, you may contact MacKenzie Partners, Inc., KCS’s proxy solicitor, at the following address and telephone numbers: MacKenzie Partners, Inc. 1407 Broadway, 27th Floor New York, New York 10018 1-800-322-2885 (Toll-Free) 1-212-929-5500 [email protected] You will not be charged for any of the documents that you request. If you would like to request documents, please do so by August 9, 2021 in order to receive them before the KCS special meeting.