McHugh debuted on Broadway in The Fall Guy, written by George Abbott and James Gleason in 1925. First National Pictures hired him as a contract player in January 1930. McHugh played everything from lead actor to sidekick and would often provide comedy relief. He appeared in more than 150 films and television productions and worked with almost every star at Warner Bros. He was a close friend of James Cagney and appeared in more Cagney movies than any other actor. He appeared with Cagney in eleven films between 1932 and 1953. Their friendship lasted until McHugh's death.
Born in Homestead, Pennsylvania of Irish descent, McHugh came from a theatrical family. His parents ran a stock theatre company and as a young child he performed on stage. His brother Matt and sister Kitty performed an act with him by the time he was ten years old, but the family quit the stage about 1930. Another brother, Ed, became a stage manager and agent in New York.
Cast as Father Timothy O'Dowd in the 1944 Bing Crosby film, Going My Way, McHugh later played william Jennings Depew in the 1962 episode "Keep an Eye on Santa Claus" in the ABC television series, Going My Way, starring Gene Kelly, and loosely based on the earlier film.
From 1954-1956, he starred in the radio program Hotel For Pets. By the 1950s, his film career had begun to decline, as evinced by his smaller role in the 1959 film Career.
From 1964 to 1965, McHugh played the role of Willie Walters, a live-in handyman in the 27-episode ABC sitcom The Bing Crosby Show, which reunited him once again onscreen with Bing Crosby. The show also co-starred Beverly Garland. McHugh's last feature film role was as a comical "sea captain" in the 1967 Elvis Presley caper film Easy Come, Easy Go. McHugh's last television appearance was as handyman Charlie Wingate in "The Fix-It Man", an episode of CBS's Lancer western series, which starred Andrew Duggan.
