Luke Timothy Grimes (born January 21, 1984) 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 older 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 television series Yellowstone (2018–2024) and in the CBS series Marshals (2026).