William Joseph Patrick O'Brien (November 11, 1899 – October 15, 1983) was an American film actor with more than 100 screen credits.

His grandfather, Patrick O'Brien, for whom he was named, was an architect who was killed while trying to break up a saloon fight in New York City.

[2] As a child, O'Brien served as an altar boy at Gesu Church, while growing up near 13th and Kilbourn Streets in Milwaukee.

O'Brien walked on stage and whispered in his ear, "For heaven's sake, Ben, put down the damn fiddle and talk to 'em."

[6]: 57  His first starring role was as ace reporter Hildy Johnson in the original 1931 version of The Front Page with Adolphe Menjou.

"[7] He was the lead in Paramount's Personal Maid (1931), and appeared in a Metro-Goldwyn-Mayer musical Flying High (1931), supporting Bert Lahr.

He was Irene Dunne's love interest in RKO's Consolation Marriage (1932), then co-starred opposite a young Bette Davis in Hell's House (1932).

[9] He was third lead to Barbara Stanwyck and Joel McCrea in Gambling Lady (1934), then was with Powell again in Twenty Million Sweethearts (1934).

"[10] O'Brien played the lead, a boxer, in The Personality Kid (1934), supported Powell in Flirtation Walk (1934) and was an auctioneer in I Sell Anything (1935).

He was a critic in love with Dolores del Río in In Caliente (1935) and had the lead in the bio-pic Oil for the Lamps of China (1935), which he called "one of my favorite pictures.

"[12] Warners gave him some starring parts: I Married a Doctor (1936), Public Enemy's Wife (1936), China Clipper (1936), The Great O'Malley (1937), and Slim (1937) with Henry Fonda.

He was Captain of the Guard (on special leave from the US Army) in San Quentin (1937) opposite Humphrey Bogart, romanced Blondell in Back in Circulation (1937) and was a veteran sailor in Submarine D-1 (1938).

O'Brien was pulled out of Swing Your Lady to co-star with Kay Francis in Women Are Like That (1938)[14] and was back with Powell for Cowboy from Brooklyn (1938).

Back at Warner Bros he was reunited with Cagney for The Fighting 69th (1940) then made Castle on the Hudson (1940) with Sheridan and John Garfield.

[17] He was in Escape to Glory (1940), then was idle for a year before making Two Yanks in Trinidad (1942) with Brian Donlevy and Flight Lieutenant (1942) with Glenn Ford.

At Universal he supported Deanna Durbin in Frank Borzage's His Butler's Sister (1943) then it was back to RKO for Marine Raiders (1944).

In 1946 he collaborated with the contralto Kate Smith on the popular Viva America program for the CBS radio network.

His close friend, Spencer Tracy, fought with his studio, MGM, to get roles for O'Brien in his films The People Against O'Hara (1951) and The Last Hurrah (1958).

In 1959 O'Brien appeared in a supporting role in one of his best-known movies as a police detective opposite George Raft in Some Like It Hot, starring Marilyn Monroe, Jack Lemmon, and Tony Curtis.

O'Brien spoke the Star Spangled Banner to the accompaniment of Doc Severinsen on trumpet for the National Anthem opening of Super Bowl IV in 1970.

In later years, O'Brien recalled that he had had three "great" movie roles in his career: Knute Rockne, Hildy Johnson in The Front Page, and Father Duffy in The Fighting 69th.

[10] Near the end of his life, he toured in a stage production of On Golden Pond, which he considered "absolutely the best play" he had ever read.

[23][24] In the late 1930s, O'Brien and a small group of his actor friends began to meet to converse and exchange opinions and stories.

Hollywood columnist Sidney Skolsky dubbed them the "Irish Mafia," but they preferred to call their social group the "Boys Club."

In addition to O'Brien, the original members of the club were James Cagney, Spencer Tracy, Allen Jenkins and Frank McHugh, all of whom were Irish-Americans.

Later Lynne Overman joined their group and then George Brent, James Dunn, Louis Calhern, William Gargan, Paul Kelly, Regis Toomey, Brian Donlevy, Ralph Bellamy, Lloyd Nolan and Frank Morgan.

President Ronald Reagan released a White House statement noting his sadness over his old friend's death.