Six Flags Entertainment Corporation/NEW

To attend online and participate in the Annual Meeting, stockholders of record will need to use their control number on their Notice of Internet Availability of Proxy Materials or your proxy card to log into the following site: www.virtualshareholdermeeting.com/FUN2026; beneficial owners who do not have a control number may gain access to the meeting by logging into their brokerage firm’s website and selecting the stockholder communications mailbox to link through to the virtual Annual Meeting. Instructions should also be provided on the voting instruction card provided by the beneficial owner’s broker, bank, or other similar organization. We encourage you to access the meeting prior to the meeting’s start time, allowing time for online check-in that begins at 11:45 a.m. EDT. If you encounter any difficulties accessing the Annual Meeting, please call the technical support number that will be posted on the virtual Annual Meeting landing page at www.virtualshareholdermeeting.com/FUN2026.

Even if you plan to attend the Annual Meeting virtually via live webcast, the Board urges you to submit your vote as soon as possible by mail, telephone, or the internet. The telephone and internet voting procedures are designed to authenticate votes cast by use of a personal identification number. These procedures allow stockholders to appoint a proxy to vote their shares of common stock and to confirm that their instructions have been properly recorded. Instructions for voting by telephone and over the internet are included on the accompanying proxy card, which solicits proxies on behalf of the Board. All of the shares of common stock represented by proxies properly received prior to or at the Annual Meeting and not revoked will be voted in accordance with the instructions indicated in the proxies. If you own shares of common stock directly and submit a proxy, on or as instructed in the accompanying form, but do not provide voting instructions on your proxy, the shares of common stock represented by your proxy will be voted for the election of the Board’s nominees as Class II directors, Mr. Haddrill, Mr. Huang, and Ms. Spiegel, and for each of Proposals Two and Three, and in the discretion of the proxies upon such other business as may properly come before the Annual Meeting, in each case whether or not any other nominations are properly made at the Annual Meeting.

If you hold shares of common stock indirectly in a brokerage account or through a bank or other nominee, you are considered to be the beneficial owner of shares of common stock held in “street name,” and these proxy materials are being forwarded to you by your broker or nominee. As the beneficial owner, you have the right to direct your broker how to vote. Under New York Stock Exchange rules, unless you furnish specific voting instructions, your broker is not permitted to vote your shares of common stock on the election of a director or on the advisory vote on executive compensation. Your broker is permitted to vote your shares of common stock on the appointment of our independent registered public accounting firm, even if you do not furnish voting instructions. If your shares of common stock are held in “street name,” your broker or other nominee may have procedures that will permit you to vote by telephone or electronically through the Internet.

Any proxy given on the accompanying form or through the internet or telephone may be revoked by the person giving it at any time before it is voted. Proxies may be revoked, or the votes reflected in the proxy changed, by submitting a properly executed later-dated proxy to Corporate Secretary, 2851 Cleveland Road, Sandusky, OH 44870, before the vote is taken at the Annual Meeting. If your shares of common stock are voted through your broker or other nominee, you must follow directions received from your broker or other nominee to change your voting instructions.

If you have more questions about the proposals, or if you would like additional copies of this document, you may call or write:

Sodali & Co

333 Ludlow Street, 5th Floor, South Tower

Stamford, CT 06902

Please call: (203)658-9400 or

Call toll free at: (800)662-5200

Email: FUN.info@investor.sodali.com

Web address: www.sodali.com

The Company has fixed the close of business on March 27, 2026 as the record date for stockholders entitled to notice of and to vote at the Annual Meeting. As of March 27, 2026, there were 101,987,541 shares of common stock outstanding and entitled to vote at the Annual Meeting, held by approximately 2,975 holders of record. Only holders of record of shares of common stock on the record date are entitled to notice of the Annual Meeting and to vote at the Annual Meeting. Each holder of record of shares of common stock as of the record date is entitled to cast one (1) vote per share of stock on each of the proposals.

Six Flags Entertainment Corporation | 2026 Proxy Statement / 65

A majority in voting power of the shares of the Company entitled to vote at the Annual Meeting, present in person or represented by proxy, will constitute a quorum. Brokernon-votes and abstentions will be counted for purposes of establishing a quorum at the Annual Meeting. The chair of the Annual Meeting shall have the power to adjourn the meeting for any reason from time to time and, if a quorum shall not be present or represented at any meeting of the stockholders, the stockholders entitled to vote thereat, present in person or represented by proxy, shall also have the power, by the affirmative vote of a majority in voting power thereof, to adjourn the meeting from time to time until a quorum shall be present or represented. Regarding Proposal One, each nominee shall be elected by a plurality of the votes cast with respect to such nominee’s election at the Annual Meeting. This means that the nominees who receive the most “for” votes are elected to the Board until all the Board seats of the applicable class of the Board for which nominees are standing for election are filled. The affirmative vote of a majority of the shares of common stock present in person or represented by proxy at the Annual Meeting and entitled to vote on the matter is required to approve Proposals Two and Three. Thesay-on-pay vote on Proposal Three is an advisory vote, and therefore even if approved by stockholders this proposal will not be binding on the Company, the People, Culture & Compensation Committee, or the Board. However, the People, Culture & Compensation Committee will consider the voting results when making future decisions regarding executive compensation as it deems appropriate.

An abstention occurs when the beneficial owner of shares, or a bank, broker or other nominee holding shares for a beneficial owner, is present at the Annual Meeting or by proxy, and entitled to vote at the meeting, but such person refrains from voting for or against a particular proposal by expressly marking the “abstain” box on the voting instruction form or ballot. A brokernon-vote occurs when a broker or other nominee does not receive voting instructions from the beneficial owner and does not have the discretion to direct the voting of the shares. As further described under Voting Process above, a broker is entitled to vote shares held for a beneficial holder on routine matters without instructions from the beneficial holder of those shares, but is not entitled to vote shares held for a beneficial holder onnon-routine items.

Withholding authority to vote your shares with respect to one or more director nominees will have no effect on the election of those nominees. Abstentions are considered present and entitled to vote and will have the effect of a vote against Proposals Two and Three. Brokernon-votes are not counted as votes cast nor shares entitled to vote and, therefore, will have no effect on the outcome of the proposals. Because Proposal Two is considered a “routine” proposal by the New York Stock Exchange, brokers are permitted to vote your shares without instruction and therefore brokernon-votes are not expected in connection with Proposal Two.