Background
Allgood was born in Dublin, Ireland, one of eight children of George and Margaret (née Harold) Allgood. Her father was Protestant and her mother Catholic. After her father"s death when she was a young girl, her mother returned to work as a furniture trader.
Allgood began work as soon as she was able, apprenticed to a French polisher near her mother"s work.
Career
Her sister was actress Maire O"Neill, from whom she was later estranged. A brother, Tom, became a Roman Catholic priest. Allgood joined Inghinidhe na hÉireann ("Daughters of Ireland"), where she first began to study drama under the direction of Maud Gonne and William Fay.
She began her acting career at the Abbey Theatre and was in the opening of the Irish National Theatre Society.
Her first big role was in December 1904 at the opening of Lady Gregory"s Spreading the News. By 1905 she was a full time actress, touring England and North America.
In 1915 Allgood was cast as the lead in Peg o" My Heart which toured Australia and New Zealand in 1916. Her happiness was short lived.
She gave birth to a daughter named Mary in January 1918, who died just a day later.
Her husband died of the flu in the outbreak of 1918 in November of that same year. After her return to Ireland Allgood continued to perform at the Abbey Theatre. Her most memorable performance was in Seán O"Casey"s Juno and the Paycock in 1923.
Allgood was frequently featured in early Hitchcock films, such as Blackmail (1929), Juno and the Paycock (1930), and Sabotage (1936).
After many successful theatre tours of America she settled in Hollywood in 1940 to pursue an acting career. She also had memorable roles in the 1941 retelling of Doctor Jekyll and Mr.
Hyde, lieutenant Happened in Flatbush (1942), Jane Eyre (1943), The Keys of the Kingdom (1944), The Spiral Staircase (1946), The Fabulous Dorseys (1947), and the original Cheaper by the Dozen (1950). Allgood became a United States citizen in 1945 and died of a heart attack in 1950 in Woodland Hills, California.