Biggins was born in Oldham, Lancashire, and brought up in Salisbury, Wiltshire, where he took elocution lessons and participated in local drama groups. His first big stage role was at the age of 17 in their Stage '65 production of Molière's Le Médecin malgré lui, where he played the lead as the hapless mistaken Doctor. This led to a job at the local repertory theatre.[2]

He has been best known as a comedy actor, appearing as the regular character Lukewarm in the popular situation comedy Porridge (1974–77) starring Ronnie Barker. Other comedy shows he appeared in include Whatever Happened to the Likely Lads? (1973) and Some Mothers Do 'Ave 'Em (1973, 1978). In 1976 he played Nero in the BBC dramatisation of I, Claudius by Robert Graves, having been selected for the role partly on the strength of a television commercial in which he had played a Roman emperor presiding over the games. He also appeared in the BBC's Poldark in 1977, and the TV miniseries Masada in 1981. Despite these serious roles, his co-hosting of Surprise, Surprise and hosting children's gameshow On Safari (1982–1985) for TVS led to him being typecast as a "bubbly personality"; when asked in 2005 if he resented this, he replied

"No, not a bit of it. I'm perfectly happy being me, thank you, and I happen to know that I am afforded enormous respect from everybody I know. And anyway, I'm having something of a second wind now. I've reached the age [57] where all kinds of roles are opening up to me."[2]

On children's television, he had a regular role as supermarket manager Adam Painting in the children's television programme Rentaghost (1978–1983) and also played Reverend Whiting in Southern Television's Brendon Chase, produced in 1980. In the early 1980s he hosted children's gameshow On Safari, a game show with a jungle-themed studio set.

Biggins was the subject of This Is Your Life in 1999 when he was surprised by Michael Aspel at the Theatre Royal, Brighton.

Biggins appeared in the Big Finish Productions audio drama The One Doctor, based on the television series Doctor Who. His film roles include The Sex Thief (1973), Eskimo Nell (1975), The Rocky Horror Picture Show (1975), Adventures of a Plumber's Mate (1978), Derek Jarman's The Tempest (1979), and "The Baker" in the 1999 Video Version of Joseph and the Amazing Technicolor Dreamcoat. His theatre roles have included "The Baker" in Joseph and the Amazing Technicolor Dreamcoat, Herod in Jesus Christ Superstar, and 18 months at the London Palladium in the stage adaptation of Chitty Chitty Bang Bang (where he was teamed in a double act with Louise Gold).

In 2008, he briefly co-presented a Sunday morning radio show on BBC London with Lesley Joseph.[3]

Biggins is well known for his performances in pantomime. His most famous role is that of "Widow Twankey" in Aladdin. He has also played "Buttons" in Cinderella.

Biggins did not perform in pantomime in Christmas 2007 however, as he was taking part in I'm a Celebrity... Get Me Out of Here!, making this the first time he has not performed in a pantomime for 38 years. Biggins was eventually voted the winner of the show on 30 November 2007. Biggins returned to pantomime the following year at the Mayflower Theatre, Southampton playing the role of Buttons in Cinderella. Biggins was the winner of the television show Celebrity Come Dine With Me, first shown on Britain's Channel Four, on 15 February 2009.

Biggins hosts an annual show West End Live in London's Leicester Square.

In 2009, he played himself as a pantomime director in the BBC Two sitcom, Psychoville. At the Southport Flower Show in August 2009, Biggins launched a new hybrid tea rose called Olivia. Sales of the rose will benefit the Claire House charity. At the end of 2009 he was in pantomime in Plymouth playing Widow Twanky.

In 2010, he was a celebrity guest team captain on What Do Kids Know? along with Rufus Hound, Joe Swash and Sara Cox on Watch.

In 2010, Biggins appeared as a guest star narrator in The Rocky Horror Show at the *Belfast Grand Opera House (March and April), at the *Sunderland Empire Theatre (June)[dated info], *Southend Cliffs Pavilion (September), *Grand Canal Theatre, Dublin and also at the *Liverpool Empire Theatre (October).

In 2010, Biggins starred in Wolverhampton's Aladdin Pantomime at the Grand Theatre.

In 2010, Biggins played God in the BBC adult puppet comedy Mongrels.

In May 2011, Biggins starred in the second series of Channel 4's Celebrity Five Go To... in which the celebrities visited South Africa.[4]

In 2011, Biggins played the part of Mrs Crusoe in Cardiff's Robinson Crusoe Pantomime, in the New Theatre.

In 2012, he was cast in the film version of Ray Cooney's farce Run For Your Wife.

In December 2012, he returned to the Theatre Royal, Plymouth in Dick Whittington.

In December 2013, he filled the role of Dame Trot alongside Bob Carolgees in a production of Jack and the Beanstalk at New Theatre, Hull.[5]

In 2014, Biggins took part in cookery programme Celebrity MasterChef.