Born in Cowes, Isle of Wight, he began his acting career in Bristol, then appeared on the London as John the Baptist opposite David Essex in Godspell. After several appearances on British television, his film debut came in 1980 in Nijinsky. The role which shot him to fame was that of Charles Ryder in the television adaptation of Evelyn Waugh's Brideshead Revisited in 1981. Brideshead brought him back together with Anthony Andrews, with whom he had appeared in The Pallisers seven years earlier. Also in 1981, he starred in the film The French Lieutenant's Woman.
In 1984 Irons won a Tony Award for his Broadway performance opposite Glenn Close in The Real Thing. In 1988 he starred in the dual role of mad twin physicians in David Cronenberg's Dead Ringers. Other films include Reversal of Fortune (for which he won the Academy Award for Best Actor), Kafka, Damage, M. Butterfly, The House of the Spirits, Lolita (remake), and Die Hard With a Vengeance. His most famous role has turned out to be the voice of Scar in The Lion King.
Married to Irish actress Sinead Cusack, and the father of 2 sons.
Filmography as actor includes