Joly was born in Beirut, Lebanon and hence speaks Arabic and French in addition to English. He may have gone to the same school as Uday Hussein and Osama Bin Laden in Beirut, although Joly is younger than both. When his parents divorced in 1987, he moved to England with his mother. Joly attended The Dragon School in Oxford (where he had his shrapnel collection confiscated).

In the 1997 UK general election, he formed the Teddy Bear Alliance and changed his name to Edward 'Teddy' Bear. Hiring out hundreds of teddy bear costumes, he staged mock protests in Westminster and received 218 votes.

Trigger Happy TV first screened on Channel 4 from 2000 to 2002. A spoof documentary about himself followed, called Being Dom Joly, and a series of Trigger Happy TV was made for a US audience in 2003.

Further to Being Dom Joly, he wrote a spoof autobiography in 2004 titled Look at ME, Look at ME!.

Following the success of Trigger Happy TV on Channel 4, he was secured by the BBC for a rumoured £1 million. However his first show for the BBC, This is Dom Joly, did not follow the success of Trigger Happy TV. In 2005, the Trigger Happy TV format was revamped on BBC TV as World Shut Your Mouth, featuring all new material; it was later released on DVD.

Also in 2005, Dom starred in a one-off documentary as part of a series on Sky One. Dom Joly's Excellent Adventure involved him travelling back to Beirut for the first time since he left in the late 1980's, and embarking on a road trip through the Syrian Desert to find a cave where he scrawled his name in as a child.

Dom Joly also writes a column for the Independent on Sunday.

He has a daughter, Parker, and a second child.