Trivia

He was the father of Paul Cusack, Sinéad Cusack, Sorcha Cusack, Niamh Cusack, Pádraig Cusack and Catherine Cusack. He was the father-in-law of Jeremy Irons. He was the grandfather of Samuel Irons, Max Irons, Megan Cusack, Beth Cooke, and Calam Lynch.

He was one of the four actors Alec Guinness most admired.

In common with Leslie French, he was offered the role of the First Doctor in the BBC television series Doctor Who (1963) but turned it down. William Hartnell was cast instead.

He tried to discourage all of his six children from pursuing the entertainment field, going so far as to not keeping a TV inside the house while they were young. Nevertheless, all of them went into some form of entertainment. Sons Paul and Padraig worked behind the scenes as director/producer types and daughters, Sinead, Sorcha, Niamh and Catherine all became actresses. In 1990 Cyril performed in an acclaimed stage production of Chekhov's "The Three Sisters" with daughters Sinead, Sorcha and Niamh at the Gate Theatre in Dublin, Ireland.

Aged six, Cusack left South Africa for Ireland, accompanied by his mother Alice Cole. He was joined by actor Brefni O'Rourke to form a theatrical troupe. He appeared on stage for the first time a year later in pantomime and dramatic performance. He led an unsettled life on the road, with brief attendances at diverse schools throughout Ireland.

He became a campaigner for conservative causes in Ireland in his later years, notably in his opposition to abortion, where he became a frequent letter-writer into the main Liberal Irish newspaper, The Irish Times. His conservative credentials came under scrutiny, however, following his death and the revelation that he had not been faithful in his first marriage, with a long-term mistress, Mary Rose Cunningham, who bore him a daughter, Catherine. Cusack married Cunningham following his first wife's death.

His father, James Cusack, was a mounted policeman in Natal Province, South Africa.

He joined the Royal Shakespeare Company in 1963 and the Old Vic in 1964.

He formed his own company and staged productions in Dublin, Paris and New York beginning in 1947.

He was educated in Newbridge College, Newbridge, Co. Kildare, and University College, Dublin, but left without a degree to join the Abbey Theatre in 1932. He received honorary doctorates in 1977 and 1980 from the NUI and the University of Dublin, respectively.

His parents separated when he was young and his mother took him to England, and then to Ireland. Cusack's mother and her subsequent partner, Breifne O'Rorke, joined the O'Brien and Ireland Players where Cyril made his theater debut at age 6.

Under his listing in Quinlan's Character Actors, published 2004, the film Lovespell (1981) was unreleased.

Lived and worked part-time in Italy throughout the 1970s.

His mother, Alice Cole, was a distant relative of London music hall star Dan Leno.

He is not the same actor as Cyril Chosack, with whom he bears no resemblance, despite the apparent similarity of their names.

In 1972 He was awarded a doctorate by the National University of Ireland,.

Appeared in two filmed adaptations of two classic sci-fi novels revolving on dystopian realities: Fahrenheit 451 (1966) (from Ray Bradbury's novel) and 1984 (1984) (from George Orwell's novel).