He was born Ian Holm Cuthbert on September 12, 1931, in Goodmayes, Essex, UK. His father, Doctor James Cuthbert, was a psychiatrist in the Essex mental asylum, where his mother, Jean Wilson worked as a nurse. Young Holm was brought up in London. At the age of seven he was inspired by the seeing 'Les Miserables' and became fond of acting. Holm studied at the Royal Academy of Dramatic Arts, graduating in 1950 to the Royal Shakespeare Company. There he emerged as an actor whose range and effortless style allowed him to play almost entire Shakespeare's repertoire. In 1959 his stage partner Laurence Olivier scored a hit on Ian Holm in a sword fight in a production of 'Coriolanus'. Holm still has a scar on his finger.

In 1965 Holm made his debut on television as Richard III on the BBC's "War of the Roses" (1965) (mini), which was a filmed theatrical production of four of Shakespeare's plays condensed down into a trilogy. In 1969 Holm won his first BAFTA Film Award Best Supporting Actor for The Bofors Gun (1968), then followed a flow of awards and nominations for his numerous works in film and on television. In 1981 Holm shot to fame with one of his best known roles, as Sam Mussabini in Chariots of Fire (1981), for which he was nominated for Oscar for Best Actor in a Supporting Role. He is best known for his big action film roles, such as Ash in Alien, Mr. M. Kurtzmann in Brazil, Father Vito Cornelius in The Fifth Element (1997), Nathan Quellen in Esther Kahn, Polonius in Hamlet (1990), as Bilbo in The Lord of the Rings: The Return of the King (2003), Terry Rapson in The Day After Tomorrow, Gideon Largeman in Garden State, Sir William Gull in From Hell (2001), Professor Fitz in The Aviator (2004), Edward Aylesbury in Chromophobia (2005), Simeon Weisz in Lord of War (2005), Ben Gurion in O'Jerusalem (2005), and as Skinner in Ratatouille