Jeremy John Irons (born 19 September 1948) is an English actor and activist. After receiving classical training at the Bristol Old Vic Theatre School, Irons began his acting career on stage in 1969 and has appeared in many West End theatre productions, including the Shakespeare plays The Winter's Tale, Macbeth, Much Ado About Nothing, The Taming of the Shrew and Richard II. In 1984, he made his Broadway debut in Tom Stoppard's The Real Thing, receiving the Tony Award for Best Actor in a Play.

Irons's break-out role came in the ITV series Brideshead Revisited (1981) and is frequently ranked among the greatest British television dramas as well as greatest literary adaptations. It would earn him a Golden Globe Award nomination. His first major film role came in the romantic drama The French Lieutenant's Woman (1981), for which he received a BAFTA nomination for Best Actor. After starring in dramas, such as Moonlighting (1982), Betrayal (1983), and The Mission (1986), he was praised for portraying twin gynaecologists in David Cronenberg's psychological thriller Dead Ringers (1988). Irons has won multiple awards, including the Academy Award for Best Actor, for his portrayal of the accused attempted murderer Claus von Bülow in Reversal of Fortune (1990).