McAvoy's first roles were in David Hayman's The Near Room in 1995 and then as Anthony Balfour in Pat Barker's Regeneration in 1997. He received his first big break was a role in the Steven Spielberg-produced miniseries Band of Brothers. His first international starring role was as Leto Atreides II in the 2003 Sci Fi Channel miniseries Frank Herbert's Children of Dune (adapted from Frank Herbert's novels). The same year he also appeared in several episodes of the BBC sitcom Early Doors and co-starred in Paul Abbott's acclaimed thriller serial State of Play. In 2004 he starred as Steve McBride in another Abbott-written drama series, Shameless on Channel 4, for which he was nominated for the British Comedy Award for Best TV Newcomer. He also appeared in Wimbledon as Paul Bettany's obnoxious brother, Carl Colt. In 2005 he starred in three productions: he played Ben in the Royal Court Theatre's production Breathing Corpses and an adaptation of Macbeth in the four-part BBC production Shak