His comedic alter ego, Desmond Olivier Dingle, is the founder, artistic director and chief executive of the two-man National Theatre of Brent, which has performed on stage, on television and on radio.
Barlow is the scriptwriter, as well as lead performer, in many National Theatre of Brent productions, in particular All the World's a Globe (1987), Desmond Olivier Dingle's Compleat Life and Works of William Shakespeare (1995) and The Arts and How They Was Done (2007).
In non-Theatre of Brent performances, he wrote and played in the four-part situation comedy for radio called The Patrick and Maureen Maybe Music Experience which ran for four weeks from January 1999.
He has also written and directed his National Theatre of Brent material for television, and played the part of Max in series 2 and the 2004 special of Absolutely Fabulous.
Barlow wrote a stage adaptation of John Buchan's novel The 39 Steps and Alfred Hitchcock's film of the same name, based on the novel, which premiered in June 2005 at the West Yorkshire Playhouse.