From Wikipedia, the free encyclopedia Jim Davis (born Marlin Davis, August 26, 1909 – April 26, 1981) was an American actor, best known for his role as Jock Ewing in the CBS prime-time soap opera, Dallas, a role which continued until he was too ill from a terminal illness to perform. He was known as Jim Davis by the time of his first major screen role, which was opposite Bette Davis in the 1948 melodrama Winter Meeting,[3] a lavish failure for which he was lambasted in the press as being too i...