
Denis O'Dea (26 April 1905 – 5 November 1978) was an Irish stage and film actor.
He was born in Dublin and attended Synge Street CBS. When very young he and his mother Kathleen (from County Kerry) moved in with her sister, who kept a boarding house at 54 South Richmond Street. He worked in insurance until taking up acting. O'Dea was a leading member of Dublin's Abbey Theatre where he had a great acting career from 1929 to 1953; a list of his performances can be found in the Abbey archives. He also appeared in numerous plays by Irish playwright Teresa Deevy, some of which toured New York and England. His work led to a number of notable film roles, including two mid-1930s John Ford films, The Informer and The Plough and the Stars (1936), and the part of the police inspector in pursuit of IRA man James Mason in Carol Reed's Odd Man Out (1947).

Treasure Island
1950 · as Dr. Livesy

Niagara
1953 · as Inspector Starkey

Under Capricorn
1949 · as Mr. Corrigan

Darby O'Gill and the Little People
1959 · as Father Murphy

Mogambo
1953 · as Father Josef

The Fallen Idol
1948 · as Inspector Crowe

Captain Horatio Hornblower R.N.
1951 · as RAdm. Sir Rodney Leighton

Sea Devils
1953 · as Lethierry

Odd Man Out
1947 · as Inspector

The Informer
1935 · as Street Singer

Esther and the King
1960 · as Mordecai

Captain Lightfoot
1955 · as Regis Donnell

I Captured the King of the Leprechauns
1959 · as Father Murphy

Beloved Enemy
1936 · as Sean's I.R.A. Friend (Uncredited)

Marry Me
1949 · as George Saunders

The Long Dark Hall
1951 · as Sir Charles Morton

The Rising of the Moon
1957 · as Police Sergeant Tom O'Hara (segment '1921')

The Plough and the Stars
1936 · as The Covey