Filed by Kansas City Southern

Pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-6

under the Securities Exchange Act of 1934

Subject Company: Kansas City Southern

Commission File No.: 333-257298

Date: July 27, 2021

YOUR VOTE IS IMPORTANT

PLEASE VOTE YOUR PROXY TODAY!

July 27, 2021

Fellow KCS Stockholder:

We recently sent you proxy materials in connection with Kansas City Southern’s (“KCS”) Special Meeting of Stockholders (the “Special Meeting”) to vote on the proposed merger with CN, to be held on August 19, 2021 at 9:00 a.m. Central Time.

At the special meeting, KCS stockholders will be asked, among other things, to consider and vote on a proposal to adopt the merger agreement with CN. KCS stockholders will receive the full merger consideration, consisting of a cash payment of $200 and 1.129 shares of CN common stock for each KCS common share, upon stockholder approval and subsequent closure into CN’s voting trust.

Opportunity to Receive Significant Premium and Participate in Substantial Upside of a Combined Company

Our proposed merger is a pro-competitive, end-to-end combination that offers unparalleled opportunities and benefits for customers, employees, shareholders, the environment and the North American economy. If the transaction is approved, KCS stockholders will realize an implied 45% premium¹ for their KCS shares and have the opportunity to participate in the upside of the combined company.

The KCS Board of Directors unanimously recommends that KCS stockholders vote “FOR” the KCS merger proposal and its other proposals, based on the compelling reasons set forth in the proxy statement dated July 7, 2021, including:

• A commitment to keeping CN and KCS major rail gateways open both physically and commercially, creating more optionality for customers to shop for the best price and service combination;

• Benefits for shippers to connect with other Class I carriers across the combined network; and

• A focus on powering the resurgence of North America’s industrial and agricultural corridors to enhance competition.

Please Vote Today! Your Vote is Extremely Important No Matter How Many Shares You Hold

The fastest and easiest way to vote is via internet. Simply follow the instructions on the enclosed proxy card, voter instruction form or email as soon as possible. You may also sign, date, and mail the enclosed proxy card in the postage-paid envelope provided.

Any questions related to the Special Meeting or the voting of shares should be directed to our proxy solicitor, MacKenzie Partners, toll-free at (800) 322-2885 or at (212) 929-5500. You may also email KSU@mackenziepartners.com.

We look forward to the successful completion of the transaction. Thank you for your continued support.

Sincerely,
	Robert J. Druten Chairman of the Board	Patrick J. Ottensmeyer President

¹  Based on KCS closing NYSE share price on March 19, 2021, last market date prior to CP deal announcement.

For more information on CN’s pro-competitive combination with KCS, please visit www.ConnectedContinent.com.

If you have any questions, require assistance with voting your proxy card,

or need additional copies of proxy material, please call MacKenzie Partners

at the phone numbers or email address listed below.

KSU@mackenziepartners.com

(800) 322-2885 or (212) 929-5500

Forward Looking Statements

Certain statements included in this document constitute “forward-looking statements” within the meaning of the United States Private Securities Litigation Reform Act of 1995 and under Canadian securities laws, including statements based on management’s assessment and assumptions and publicly available information with respect to CN and KCS, regarding the proposed transaction between CN and KCS, the expected benefits of the proposed transaction and future opportunities for the combined company. By their nature, forward-looking statements involve risks, uncertainties and assumptions. CN and KCS caution that their assumptions may not materialize and that current economic conditions render such assumptions, although reasonable at the time they were made, subject to greater uncertainty. Forward-looking statements may be identified by the use of terminology such as “believes,” “expects,” “anticipates,” “assumes,” “outlook,” “plans,” “targets,” or other similar words.

Forward-looking statements are not guarantees of future performance and involve risks, uncertainties and other factors which may cause actual results, performance or achievements of CN, or the combined company, to be materially different from the outlook or any future results, performance or achievements implied by such statements. Accordingly, readers are advised not to place undue reliance on forward-looking statements. Important risk factors that could affect the forward-looking statements in this document include, but are not limited to: the outcome of the proposed transaction between CN and KCS; the parties’ ability to consummate the proposed transaction; the conditions to the completion of the proposed transaction; that the regulatory approvals required for the proposed transaction may not be obtained on the terms expected or on the anticipated schedule or at all; CN’s indebtedness, including the substantial indebtedness CN expects to incur and assume in connection with the proposed transaction and the need to generate sufficient cash flows to service and repay such debt; CN’s ability to meet expectations regarding the timing, completion and accounting and tax treatments of the proposed transaction; the possibility that CN may be unable to achieve expected synergies and operating efficiencies within the expected time-frames or at all and to successfully integrate KCS’ operations with those of CN; that such integration may be more difficult, time-consuming or costly than expected; that operating costs, customer loss and business disruption (including, without limitation, difficulties in maintaining relationships with employees, customers or suppliers) may be greater than expected following the proposed transaction or the public announcement of the proposed transaction; the retention of certain key employees of KCS may be difficult; the duration and effects of the COVID-19 pandemic, general economic and business conditions, particularly in the context of the COVID-19 pandemic; industry competition; inflation, currency and interest rate fluctuations; changes in fuel prices; legislative and/or regulatory developments; compliance with environmental laws and regulations; actions by regulators; the adverse impact of any termination or revocation by the Mexican government of KCS de México, S.A. de C.V.’s Concession; increases in maintenance and operating costs; security threats; reliance on technology and related cybersecurity risk; trade restrictions or

other changes to international trade arrangements; transportation of hazardous materials; various events which could disrupt operations, including illegal blockades of rail networks, and natural events such as severe weather, droughts, fires, floods and earthquakes; climate change; labor negotiations and disruptions; environmental claims; uncertainties of investigations, proceedings or other types of claims and litigation; risks and liabilities arising from derailments; timing and completion of capital programs; and other risks detailed from time to time in reports filed by CN with securities regulators in Canada and the United States. Reference should also be made to Management’s Discussion and Analysis in CN’s annual and interim reports, Annual Information Form and Form 40-F, filed with Canadian and U.S. securities regulators and available on CN’s website, for a description of major risk factors relating to CN. Additional risks that may affect KCS’ results of operations appear in Part I, Item 1A “Risks Related to KCS’ Operations and Business” of KCS’ Annual Report on Form 10-K for the year ended December 31, 2020, and in KCS’ other filings with the U.S. Securities and Exchange Commission (“SEC”).

Forward-looking statements reflect information as of the date on which they are made. CN and KCS assume no obligation to update or revise forward-looking statements to reflect future events, changes in circumstances, or changes in beliefs, unless required by applicable securities laws. In the event CN or KCS does update any forward-looking statement, no inference should be made that CN or KCS will make additional updates with respect to that statement, related matters, or any other forward-looking statement.

No Offer or Solicitation

This document does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

Additional Information and Where to Find It

In connection with the proposed transaction, CN has filed with the SEC a registration statement on Form F-4 to register the shares to be issued in connection with the proposed transaction, and the registration statement has been declared effective. CN has filed with the SEC its prospectus and KCS has filed with the SEC its definitive proxy statement in connection with the proposed transaction, and the KCS proxy statement is being sent to the stockholders of KCS seeking their approval of the merger-related proposals. This document is not a substitute for the registration statement, the prospectus, the proxy statement or other documents CN and/or KCS may file with the SEC or applicable securities regulators in Canada in connection with the proposed transaction.

INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT, THE PROSPECTUS, THE PROXY STATEMENT AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC OR APPLICABLE SECURITIES REGULATORS IN CANADA CAREFULLY IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE (INCLUDING ALL AMENDMENTS AND SUPPLEMENTS THERETO) BECAUSE THEY CONTAIN AND WILL CONTAIN IMPORTANT INFORMATION ABOUT CN, KCS AND THE PROPOSED TRANSACTION. Investors and security holders may obtain copies of these documents (if and when available) and other documents filed with the SEC and applicable securities regulators in Canada by CN free of charge through at www.sec.gov and www.sedar.com. Copies of the documents filed by CN (if and when available) will also be made available free of charge by accessing CN’s website at www.CN.ca. Copies of the documents filed by KCS (if and when available) will also be made available free of charge at www.investors.kcsouthern.com, upon written request delivered to KCS at 427 West 12th Street, Kansas City, Missouri 64105, Attention: Corporate Secretary, or by calling KCS’ Corporate Secretary’s Office by telephone at 1-888-800-3690 or by email at corpsec@kcsouthern.com.

Participants

This document is neither a solicitation of a proxy nor a substitute for the registration statement, the prospectus, the proxy statement or other filings that may be made with the SEC and applicable securities regulators in Canada. Nonetheless, CN, KCS, and certain of their directors and executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information about CN’s executive officers and directors is available in its 2021 Management Information Circular, dated March 9, 2021, as well as its 2020 Annual Report on Form 40-F filed

with the SEC on February 1, 2021, in each case available on its website at www.CN.ca/investors/ and at www.sec.gov and www.sedar.com. Information about KCS’ directors and executive officers may be found on its website at www.kcsouthern.com and in its 2020 Annual Report on Form 10-K filed with the SEC on January 29, 2021, available at www.investors.kcsouthern.com and www.sec.gov. Additional information regarding the interests of such potential participants is or may be included in the registration statement, the prospectus, the proxy statement or other documents filed with the SEC and applicable securities regulators in Canada if and when they become available. These documents (if and when available) may be obtained free of charge from the SEC’s website at www.sec.gov and from www.sedar.com, as applicable.

KANSAS CITY SOUTHERN LINES ENDORSEMENT LINE SACKPACK MR A SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext C123456789 Your vote matters – here’s how to vote! You may vote online or by phone instead of mailing this card. Online Go to www.envisionreports.com/KSUSPECIAL or scan the QR code – login details are located in the shaded bar below. Phone Call toll free 1-800-652-VOTE (8683) within the USA, US territories and Canada Save paper, time and money! Sign up for electronic delivery at www.envisionreports.com/KSUSPECIAL Using a black ink pen, mark your votes with an X as shown in this example. Please do not write outside the designated areas. Special Meeting Proxy Card 1234 5678 9012 345 IF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE. A Proposals – The Board of Directors recommends a vote FOR the following proposals: 1. To adopt the Agreement and Plan of Merger, dated as of May 21, 2021 (as it may be amended from time to time, the “merger agreement”) by and among Kansas City Southern (“KCS”), Canadian National Railway Company (“CN”) and Brooklyn Merger Sub, Inc., a wholly owned subsidiary of CN (the “merger proposal”). For Against Abstain 2. 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. For Against Abstain 3. To approve the adjournment of the KCS special meeting, if necessary or appropriate, to solicit additional proxies if there are not sufficient votes at the time of the KCS special meeting to approve the merger proposal or to ensure that any supplement or amendment to this proxy statement/prospectus is timely provided to KCS shareholders. B Authorized Signatures – This section must be completed for your vote to count. Please date and sign below. Please sign exactly as name(s) appears hereon. Joint owners should each sign. When signing as attorney, executor, administrator, corporate officer, trustee, guardian, or custodian, please give full title. Date (mm/dd/yyyy) – Please print date below. Signature 1 – Please keep signature within the box. Signature 2 – Please keep signature within the box. C 1234567890 J N T 1UPX 510070 MR A SAMPLE (THIS AREA IS SET UP TO ACCOMMODATE 140 CHARACTERS) MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND

The Special Meeting of Stockholders of Kansas City Southern will be held on Thursday, August 19, 2021 at 9:00 a.m. Central Time, virtually via the internet at meetings.computershare.com/MUKQC2H To access the virtual meeting, you must have the information that is printed in the shaded bar located on the reverse side of this form. Important notice regarding the Internet availability of proxy materials for the Special Meeting of Stockholders. The material is available at: www.envisionreports.com/KSUSPECIAL Small steps make an impact. Help the environment by consenting to receive electronic delivery, sign up at www.envisionreports.com/KSUSPECIAL IF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE. KANSAS CITY SOUTHERN Notice of Special Meeting of Stockholders Proxy Solicited by Board of Directors for Special Meeting – August 19, 2021 Robert J. Druten, Antonio O. Garza, Jr. and Patrick J. Ottensmeyer, or any of them, each with the power of substitution, are hereby authorized to represent and vote the shares of the undersigned, with all the powers which the undersigned would possess if personally present, at the Special Meeting of Stockholders of Kansas City Southern to be held on August 19, 2021 or at any postponement or adjournment thereof. Shares represented by this proxy will be voted by the stockholder. If no such directions are indicated, the Proxies will have authority to vote FOR items 1, 2 and 3. In their discretion, the Proxies are authorized to vote upon such other business as may properly come before the meeting. (Items to be voted appear on reverse side) C Non-Voting Items Change of Address – Please print new address below. Comments – Please print your comments below.