From Wikipedia, the free encyclopedia Thomas Mitchell (July 11, 1892 – December 17, 1962) was an American actor, playwright and screenwriter. Among his most famous roles in a long career are those of Gerald O'Hara, the father of Scarlett O'Hara in Gone with the Wind, the drunken Doc Boone in John Ford's Stagecoach, and Uncle Billy in It's a Wonderful Life. Mitchell was the first person to win an Oscar, an Emmy, and a Tony Award.