William Gargan, born William Dennis Gargan, was born on July 17, 1905, in Brooklyn, New York, USA, and died on February 17, 1979, at the age of 73 on a flight between New York and San Diego.

He was an American film, television, and radio actor. Gargan played character roles in many Hollywood productions, including twice playing the role of detective Ellery Queen, but he was best known for his role as detective Martin Kane in the 1949–1951 radio and television series Martin Kane, Private Eye, sponsored by U.S. Tobacco. He also appeared as a private detective in the NBC radio program Barry Craig, Confidential Investigator, which aired from 1951 to 1955.