He began acting with the National Youth Music Theatre in 1987, and had his first television role in 1989. After starring in films directed by Andrew Niccol, Clint Eastwood and David Cronenberg, he was nominated for the Academy Award for Best Supporting Actor in 1999 for his performance in Anthony Minghella's The Talented Mr. Ripley. In 2000 he won a Best Supporting Actor BAFTA Award for his work in the film. In 2003, he was nominated for the Academy Award for Best Actor for his performance in another Minghella film, Cold Mountain. He is also known for his role as Dr. John Watson in the 2009 film Sherlock Holmes and its 2011 sequel, Sherlock Holmes: A Game of Shadows.
In 2006, he was ranked as one of the top ten most bankable film stars in Hollywood. In 2007, he received an Honorary César and he was named a Chevalier of the Ordre des Arts et des Lettres by the French government. He was a member of the main competition jury at the 2011 Cannes Film Festival.