He was the younger brother of film director Raoul Walsh. He attended the High School of Commerce in New York City where he was graduated in the Class of 1911, competed on the baseball, track, cross country, swimming and crew teams and was a member of the Omega Gamma Delta Fraternity, like his older brother. At various future dates he attended Fordham and Georgetown Universities.
Walsh was originally intended to play Ben-Hur in the Italian shoot that began with Goldwyn Pictures in 1923 and inherited by Metro-Goldwyn-Mayer after the 1924 merger of Metro Studios, Goldwyn Pictures, and Louis B. Mayer Studios. Midway through production, Walsh and director Charles Brabin were replaced by Ramon Novarro and director Fred Niblo.
From 1916 to 1926, Walsh was married to actress Seena Owen and they had a daughter named Patricia.
He was born in New York, New York and died in Pomona, California from pneumonia.