Broadbent was born in Lincoln, the son of Doreen "Dee" (née Findlay), a sculptor, and Roy Laverick Broadbent, an artist, sculptor, interior designer and furniture maker who turned a former church into a theatre named after him.
Broadbent's parents were both amateur actors who co-founded the Holton Players acting troupe at Holton cum Beckering; the two were described by the BBC as conscientious objectors who "worked the land" rather than participate in World War II.
Broadbent had a twin sister who died at birth.
He was educated at Leighton Park School, a Quaker school in Reading, and briefly attended art college before transferring to the London Academy of Music and Dramatic Art, from which he graduated in 1972.
Broadbent's early stagework included a number of productions for The National Theatre of Brent, as the downtrodden assistant Wallace to Patrick Barlow's self important actor/manager character Desmond Olivier Dingle. Broadbent and Barlow played many male and female character roles in comically less than epic tellings of historical and religious stories, such as The Messiah, The Complete Guide to Sex, The Greatest Story Ever Told (the story of Jesus), Revolution!!, All The World's A Globe (Shakespeare).
These were hits at the Edinburgh Fringe, in London and on tour.
Broadbent made his film debut in 1978 with a tiny role in Jerzy Skolimowski's The Shout, and made his television debut the following year. He went on to work with Stephen Frears (for television), and in The Hit (1984)), and Terry Gilliam (in Time Bandits (1981) and Brazil (1985)) before establishing himself in Mike Leigh's Life Is Sweet (1990).
He proved his ability as a character actor in films, and played "The Shy Doctor" in the 1999 Comic Relief parody 'Doctor Who' sketch, Doctor Who and the Curse of Fatal Death.
In 2001, Broadbent starred in three of the year's most successful films: Bridget Jones's Diary, Moulin Rouge!, for which he won a BAFTA, and Iris, for which he won an Oscar for his portrayal of John Bayley. He is regarded as one of cinema's most reliable character actors, and has a reputation of being very easy to work with.
Broadbent also appeared as DCI Roy, in The Slag Slater, an associate character in the enormously popular sitcom Only Fools and Horses. Broadbent had originally been offered the lead role of Del Trotter in the series, but he turned it down due to other commitments. He has also played a role in the Inspector Morse series.
Other comic roles include the lead role in the sitcom The Peter Principle, and occasional guest appearances in Not The Nine O'Clock News and Victoria Wood As Seen On TV. He played Don Speekingleesh in The Queen of Spain's Beard in the first series of The Black Adder in 1983. He also played the role of Prince Albert in Blackadder's Christmas Carol, first broadcast in 1988. He joined Rowan Atkinson again in his Spider-Man spoof, Spider-Plant Man, as a disgruntled Batman, jealous of Spider-Plant Man's success.
Broadbent played the title role in Channel 4 drama, Longford, in October 2006, earning a BAFTA TV Award, a Golden Globe and a 2007 Emmy nomination for his performance. Broadbent appeared as Inspector Frank Butterman in Hot Fuzz in 2007, which the film received very high appraise.
Broadbent is married to painter and former theatre designer, Anastasia Lewis.
- A curious coincidence is that Jim Broadbent, who plays Digory in the movie, played Professor Slughorn in the Harry Potter movies, which is coincidental as J.K. Rowling named two of her characters (Cedric Diggory and Kirke) after Digory.
- In 2016, Jim Broadbent was announced to have joined the hit HBO show Game of Thrones, an adaption of the popular Song of Ice and Fire series, for a currently unknown role in the show's seventh season. This means that Jim has portrayed roles in three of the most well-known fantasy series adaptions: Chronicles of Narnia, Game of Thrones, and Harry Potter.