Martin Sheen Sheen was born in Dayton, Ohio. He lived on Brown Street in the South Park neighborhood, and was one of 10 siblings (9 boys and one girl). He attended Chaminade High School. He is a devout Roman Catholic, born to a Spanish-born father, Francisco Estevez, and an Irish mother, Mary Anne Phelan. Phelan, from County Tipperary, fled Ireland during the Irish War of Independence due to her family's Old IRA connections. Sheen adopted his stage name in honor of Catholic archbishop and theologian Fulton J. Sheen.
Sheen had wanted to act since he was very young, but his father disapproved. He deliberately flunked the entrance exam for the University of Dayton so that he could pursue his goal. (He has, however, credited the Marianists at that university as a major influence on his public activism.) Sheen borrowed money from a priest and headed to New York City while enduring the struggling actor route. He developed a theater company with other actors in hopes that a production would earn him notice. His first major role was on Broadway, in The Subject Was Roses, which he recreated in the 1968 film of the same name. He did not receive another important part until 1973, when he starred with Sissy Spacek in the crime drama Badlands.