U.S. Agent

U.S. Agent (John Walker) is a character appearing in American comic books published by Marvel Comics, usually those starring Captain America and the Avengers. Created by Mark Gruenwald and Paul Neary, the character first appeared in Captain America #323 (November 1986) as Super-Patriot. He was later redesigned as an incarnation of Captain America and a few years later, as U.S. Agent. Wyatt Russell portrays John Walker in the Marvel Cinematic Universe, starting with the streaming television series The Falcon and the Winter Soldier (2021) and the film Thunderbolts* (2025). He will reprise the role in Avengers: Doomsday (2026).