He is known for his time on Channel 31's Studio A, Channel 9's Comedy Inc. and Channel 10's The Project. He has also appeared at several Melbourne International Comedy Festival Galas, and done voice-over work for Holden. In 2013, he was one of the four hosts on panel show This Week Live. He currently works at Fox FM as a part of its breakfast team, alongside Fifi Box.
Thornton hosted a weekly comedy/variety podcast entitled Slapbang Radio with fellow comedian Tommy Little; as well as a radio show entitled Mama Mia with Em Rusciano. He has also been on shows such as The Circle and The Trophy Room.
Dave has appeared on The Little Dum Dum Club eight times. The first was the podcast's fourth episode, which was posted on November 16, 2010 and was the first known instance of Tommy acknowledging that "Dassalo" is not his real last name. Thornton returned, along with guest Jimmy James Eaton, for the 68th episode of the show. The episode was posted on January 18th, 2012.
Dave's next apperance came at a live episode alongside Yumi Stynes, Luke McGregor and Nick Cody. In April 2012, he returned for a live episode, this time with guests Celia Pacquola and Tony Martin. Thornton returned as a standalone guest on the show's 137th episode. His 2014 appearances include an episode with Dilruk Jayasinha (176), a live episode as a part of the Melbourne International Comedy Festival with McGregor and Greg Behrendt (185) and an episode with Asher Trealeven (197).