He grew up in Glasgow, moving with his grandparents after his parents divorced when he was 7. As a child, he thought of becoming a missionary and later considered joining the navy before acting caught his attention. McAvoy went to the Royal Scottish Academy of Music and Drama to study acting.
At the age of 20, McAvoy moved to London, hoping to advance his career. He landed some film and television work in England, appearing on such shows as The Inspector Lynley Mysteries and Foyle’s War. In the United States, McAvoy also won roles on the critically acclaimed 2001 miniseries Band of Brothers about World War II and the 2003 science fiction miniseries Children of Dune based on the book by Frank Herbert.
Taking on the decidedly less family-friendly fare, McAvoy played a fictional counterpart to the tyrannical Ugandan president, Idi Amin, in The Last King of Scotland. The film shows the charisma and brutality of Amin, played by Forest Whitaker, largely through the eyes of McAvoy’s character, Dr. Nicholas Garrigan, a Scottish doctor. After a chance meeting, Garrigan becomes Amin’s personal physician. At first charmed by Amin, Garrigan eventually sees light about the vicious ruler and suffers at his hands as a result. For his performance, McAvoy was nominated for a BAFTA Film Award for Best Actor in a Supporting Role in 2007.
His big break came while playing a faun named Mr. Tumnus in the hit film The Chronicles of Narnia: The Lion, the Witch, and the Wardrobe. Prominent opportunities followed, including roles in The Last King of Scotland, Becoming Jane, Atonement, Wanted and X-Men: First Class. McAvoy won a BAFTA Film Award for Orange Rising Star Award.