He appeared at Montreal's Just For Laughs festival in 1998, and made stand-up appearances on BBC One, Channel 4 and Five before finding success with The Boosh.

The double-act made their debut at the 1998 Edinburgh and Sydney festivals, earning them the Perrier best newcomer award, and returned to Edinburgh in 1999, when they were nominated for the main award, 2000 and 2001. The 2000 show, Autoboosh, won the equivalent Barry award at the Melbourne International Comedy Festival.

The Boosh was picked up by Radio4 in 2001 for a series which won the first and only Douglas Adams Award for Innovative Comedy Writing. The show transferred to BBC Three for two series in 2004 and 2005, giving them a cult success that enabled them to embark on a major nationwide tour in 2006.

As an actor, Barratt has appeared in the Channel 4 adaptation of Zadie Smith's White Teeth, Garth Marenghi's Darkplace and independent films including The Reckoning and Mexicano (both 2002).