With his paternal grandparents originally immigrants from Spain and Ireland, Sheen wanted to take on a more American name. His children share the Sheen surname.

According to a 2003 "Inside the Actors Studio" interview, Martin Sheen revealed he took his name from CBS casting director Robert Dale Martin, who gave him his big break, and a Catholic televangelist, Fulton J. Sheen, whom he thought was a great actor. Unlike his son Charlie, Martin never legally changed his name.

Emilio Estevez (right), of course, kept his name.