Sheen was born on August 3, 1940 in Dayton, Ohio, the son of Mary-Ann (née Phelan; 1903–1951) and Francisco Estévez Martinez (1898–1974). Both of Sheen's parents were immigrants, his father from Parderrubias, Galicia, Spain and his mother from Borrisokane, County Tipperary, Ireland.

After moving to Dayton in the 1930s, his father was a factory worker/machinery inspector at the National Cash Register Company. Sheen grew up on Brown Street in the South Park neighborhood, one of ten children (nine boys and a girl).

Martin Sheen's Family Tree