The Annual Meeting of Stockholders of HF Sinclair Corporation (the “Annual Meeting”) will be held on Wednesday, May 14, 2025, at 8:30 a.m. Central Daylight Time, in a virtual meeting format only via webcast at www.virtualshareholdermeeting.com/DINO2025. To attend and participate in the Annual Meeting webcast, you will need the 16-digit control number included on your proxy card, voting instruction form or notice of internet availability. Beneficial stockholders who do not have a control number may gain access to the Annual Meeting by logging into their brokerage firm’s website and selecting the stockholder communications mailbox. We encourage you to access the Annual Meeting prior to the start time. Online access and check-in will begin at 8:15 a.m., Central Daylight Time.