In 1983, Firth starred in the award-winning London stage production of Another Country, and reprised his role for his first film appearance in 1984. In 1987, he appeared alongside Kenneth Branagh in the film version of J. L. Carr’s novel, A Month in the Country. In 1989, he took the lead in the film Valmont.
Following these earlier roles, it was in the 1995 BBC television adaptation of Jane Austen’s classic Pride and Prejudice that Firth gained wider renown. The serial was a major international success, and Firth became known as a heartthrob because of his role as Fitzwilliam Darcy. This performance also made him the object of affection for fictional journalist Bridget Jones (created by Helen Fielding), an interest which carried on into the two novels featuring the Jones character. In the second novel, Bridget Jones: The Edge of Reason, the character even meets Firth in Rome. As something of an in-joke, when the novels were adapted for the cinema, Firth was cast as Jones’s love interest, Mark Darcy. Continuing this in-joke there was a dog called Mr Darcy in the film St. Trinian’s which Colin’s character accidentally kills.
Firth had a supporting role in The English Patient (1996) and since then has starred in films such as Fever Pitch (1997), Shakespeare in Love (1998), Bridget Jones’s Diary (2001), The Importance of Being Earnest (2002), Love Actually (2003), What a Girl Wants (2003) and Bridget Jones: The Edge of Reason (2004). He has also appeared in recent television productions, including Donovan Quick (an updated version of Don Quixote) (1999) and Conspiracy (2001). In 2007, Firth starred with Aishwarya Rai in The Last Legion.
Firth is also a Jury Member for the on going Filmaka amateur short film contest.