Biggins was born in Oldham, Lancashire, England and raised in Salisbury, Wiltshire, where he took elocution lessons and participated in local drama groups, leading to a job at the local repertory theatre.
He was 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. 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  where all kinds of roles are opening up to me.”
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 bizarre afternoon game show with a jungle-themed studio set.
Biggins appeared in the Big Finish Productions audio drama The One Doctor, based on the television series Doctor Who. His film roles include The Rocky Horror Picture Show (1975) 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.
Biggins is well known for his performances in pantomime. His most famous role is that of “Widow Twankey” in the traditional British pantomime, 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 November 30, 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 is to appear 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 Pavillion (September), *Grand Canal Theater Dublin and also at the *Liverpool Empire Theatre (October).
In 2010 Biggins will star in Wolverhampton’s Pantomime at The Grand Theatre.
In 2010 Biggins played God in the BBC adult puppet comedy Mongrels (TV series).