Television

Williamson is widely known for his portrayal of the foolish, hapless Barry Evans in the BBC soap opera EastEnders, a role that he played from 1994 to 2004. This was Williamson's second role in the soap; he previously had a brief role as a paramedic earlier in 1994. In 2009, he stated that he had no regrets about leaving the show.^[3]

Williamson was the subject of This Is Your Life in 2001. In 2004, Williamson appeared on and won an episode of Celebrity Stars in Their Eyes, impersonating the singer Meat Loaf. Williamson finished third in the 2007 series of Comic Relief does Fame Academy. Other television roles have included parts in the detective series Inspector Morse, the ITV drama London's Burning, the BBC sitcom Waiting for God, the Ricky Gervais and Stephen Merchant comedy Extras as a send-up of himself and as Balbus, a midlife crisis afflicted Roman charioteering instructor in historical comedy series Plebs

Williamson competed in Celebrity Big Brother 20, and became the eighth housemate to be evicted, on day 23. Most recently, in 2020, Williamson appeared as recurring character Chris Smith, future father-in-law to the titular character played by Spencer Jones in the BBC Two sitcom, Mister Winner. He reprised the role from the pilot which had previously been broadcast in 2017 on BBC One.^[4]

Stage

Stage roles have included Monty the DJ in the West End run and UK tour of Saturday Night Fever, and appearing at Canterbury's Marlowe Theatre from December 2003 to January 2004 in a pantomime production of Snow White and the Seven Dwarfs, alongside Toyah Willcox.^[5] In 2006 he starred in the pantomime Dick Whittington at The Playhouse in Weston-super-Mare. He returned to the Marlowe Theatre from December 2007 to January 2008, in Aladdin, alongside Stephen Mulhern. During 2008 he played Nathan Detroit in the touring production of Guys and Dolls, having already appeared in the part in the West End. In 2008–2009, he was again appearing in Aladdin, this time at the Wyvern Theatre, Swindon. In May 2006, Williamson played the lead in the play Road to Nirvana at The King's Head Theatre London and in October 2006, appeared in a sketch as part of the charity benefit The Secret Policeman's Ball which was staged at the Royal Albert Hall.^[6]

In 2009, Williamson toured the UK playing habitual criminal Norman Stanley Fletcher in a stage version of the classic TV comedy Porridge. The script had been newly written by the series' co-authors, Dick Clement and Ian La Frenais.^[7] In 2012 he toured in The Ladykillers. He played Baron Bomburst and Lord Scrumptious in the UK tour production of Chitty Chitty Bang Bang.^[8]

Radio

In 2018, Williamson wrote a BBC radio drama series titled Eden's End, set in the Kent hop picking season of 1939. The series starred Shane Taylor (Band of Brothers), Steve Nallon (Spitting Image) and Candis Nergaard (Call the Midwife).

Quizzing

Williamson spent a year competing in the UK Quiz Grand Prix as research for his book A Matter Of Facts which details the world of elite general knowledge quizzing competitions.^[9] During this time he became a Top 50 ranked player in the UK. During an appearance on ITV's Beat the Chasers (in which he won £120,000 for The Paul Strank Charitable Trust based in south London), the Dark Destroyer described him as "celebrity quizzing royalty".^[10]

Television

Film

Music video