Luke Timothy Grimes is an American actor and musician. He is known for his role as Navy SEAL Marc Alan Lee in the film American Sniper. He played Christian Grey's brother, Elliot, in the film Fifty Shades of Grey (2015), and its sequels, Fifty Shades Darker (2017) and Fifty Shades Freed (2018). He starred as Kayce Dutton in the Paramount Network drama series Yellowstone (2018–2024).