Sebastian Stan (born August 13, 1982) is a Romanian-born American actor. He gained recognition for his role as Bucky Barnes / Winter Soldier in the Marvel Cinematic Universe media franchise, beginning with the film Captain America: The First Avenger (2011), and serving as a lead actor in the Disney+ miniseries The Falcon and the Winter Soldier (2021) and the film Thunderbolts*( 2025). On television, Stan played Carter Baizen in Gossip Girl (2007–2010) and the Mad Hatter in Once Upon a Time (201...