Exhibit 32.1

CERTIFICATION OF CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Selim Bassoul, as President and Chief Executive Officer of Six Flags Entertainment Corporation (the “Company”) certify, pursuant to 18 U.S.C. § 1350, as adopted by Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

(1)the accompanying quarterly report on Form 10-Q for the period ending October 1, 2023 as filed with the U.S. Securities and Exchange Commission (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

(2)the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: November 13, 2023
	/s/ SELIM BASSOUL
	Selim Bassoul
	President and Chief Executive Officer