Film roles include Ricky in Mike Leigh's Career Girls (1997), Phil in the 2001 cult British independent film Mr In-Between, and the British comedy Three and Out (2008). Benton featured in all three of The Booze Cruise episodes, with Martin Clunes and Brian Murphy, among others.

Benton has a recurring role as Father McBride in the James Nesbitt series Murphy's Law and has starred with Vic and Bob in the series Randall and Hopkirk (Deceased) (remake), Catterick, and Monkey Trousers. He also appeared as an Earthly representative of the Devil in the 2003 ITV drama The Second Coming, and the 2005 ITV drama Planespotting. From 1995 to 2003 Benton played Martin Pond in sitcom Barbara. He has also starred in the BBC Three comedy I'm with Stupid and in the Doctor Who episode "Rose" as conspiracy theorist Clive. In late 2008, Benton starred in the ITV drama Britannia High and co-stars in Scoop, in which he plays Max de Lacey. Benton co-starred in the Roman Mysteries episode "The Slave Girl from Jerusalem".

Benton played the role of the bank manager in a string of 8 television commercials for the Nationwide Building Society, directed by Armando Iannucci, shown from 2004 to 2010.

Other roles have included Connor in Afterlife (2005), Dad in The Imaginarium of Doctor Parnassus (2009), Hustle (2010), and Farmer Finch in the BBC's Land Girls.

In April 2008, Benton appeared as Jess Yates in the BBC Four drama Hughie Green, Most Sincerely.

On BBC Radio 4, Benton starred as the optimistic title character Harvey Easter in Mr Blue Sky, written by Andrew Collins and broadcast in May and June 2011. A second series is due for May 2012. Benton has also played Fred the butcher in the televised series of episodes by Catherine Cookson.

In 2012, Benton appeared in the one-off special Panto! as Francis, the Director of the play. In July 2012, it was announced that Benton would star as Edna Turnblad in the 2013 UK tour of Hairspray the Musical, starting in February 2013 and finishing in September 2013.

In September 2013, Benton became one of the contestants in the eleventh series of the BBC One talent show Strictly Come Dancing, where he was partnered with world dancing champion Iveta Lukosiute. The couple left the show on week 10 after losing the public vote.

In 2015 Benton appeared as Police Constable Walt Everett in the BBC daytime series Father Brown, episode 3.12 "The Standing Stones". He also appeared as Les in the "La Couchette", the first episode of the second series of anthology series Inside No. 9. In 2015, Benton presented the BBC One daytime game show The Edge for its first series, being replaced by Gabby Logan.

On the 21 August 2016, Benton played Bottom in A Midsummer Night's Dream (Mendelssohn) in the BBC prom 48. Benton appeared as a bartender in the December 2016 Christmas Special of British Sitcom Outnumbered.

In 2017, he played Dennis Feldman in the ITV drama, The Halcyon

As of February 2018, Benton is currently starring as Frank Hathaway, alongside Actress Jo Joyner in the new BBC daytime comedy drama Shakespeare & Hathaway - Private Investigators