A Special Meeting of Stockholders of HF Sinclair Corporation will be held on Tuesday, November 28, 2023, at 9:30 a.m. Central Time, in a virtual meeting format only. Stockholders of record as of the close of business on October 23, 2023 will be able to vote and ask questions online during the meeting. If you would like to attend the virtual meeting and have your 16-digit control number included on your proxy card, please go to www.virtualshareholdermeeting.com/DINO2023SM 15 minutes before the start of the meeting to log in.

If you hold your shares of HF Sinclair Common Stock in the name of a bank, broker or other nominee, you should follow the instructions provided by your bank, broker or other nominee when voting your shares of HF Sinclair Common Stock.