Ramón Antonio Gerardo Estévez (born August 3, 1940), known by his stage name Martin Sheen, is an American actor. He first became known for his roles in the films The Subject Was Roses (1968) and Badlands (1973), and later gained wide recognition for his leading role as Captain Benjamin Willard in Apocalypse Now (1979), for his role as U.S. President Josiah Bartlet in the television series The West Wing (1999–2006), and for his role as Robert Hanson in the Netflix television series Grace and Frankie (2015–2022).

In film, Sheen won the Best Actor Award at the San Sebastián International Film Festival for his performance as Kit Carruthers in Badlands. For his portrayal of Captain Willard in Apocalypse Now, Sheen was nominated for a BAFTA Award for Best Actor.

Sheen has worked with a wide variety of directors, including Richard Attenborough, Francis Ford Coppola, Terrence Malick, David Cronenberg, Mike Nichols, Martin Scorsese, Steven Spielberg, and Oliver Stone. In 1989, Sheen received a star on the Hollywood Walk of Fame. On television, Sheen earned a Golden Globe Award and two Screen Actors Guild Awards for his role as President Josiah Bartlet in The West Wing, as well as an Emmy Award for his guest appearance on the sitcom Murphy Brown. In 2012, he played Uncle Ben in the film The Amazing Spider-Man, directed by Marc Webb.

Born and raised in the United States to a Spanish father and an Irish mother; he took the stage name Martin Sheen to make it easier for him to get acting roles. Father of four children, all of whom became actors.