Comedy Slapdown is an Australian television improvised comedy program produced by FremantleMedia, that first aired on The Comedy Channel from 8 November 2008 at 7:30pm. The show is hosted by H.G. Nelson and feaures a variety of comedians participating in theatresports Matt Parkinson heads up the judging panel which includes one other celebrity judge and one judge selected from the audience. Notable guest comedians include Corinne Grant, Tom Gleeson, Natalie Garonzi, Matt Tilley and Julia Zemiro. The premise of the show can be compared to the popular improvisational comedy program 'Whose Line Is It Anyway?' with various improvisational comedy games played as the teams compete against each other.

On the voyage from Old Earth to New Earth, a freak accident causes the Dogstar, a giant space ark containing all of the world's dogs, to become lost to mankind.

In this improvisational comedy competition, four guest stars walk into a live improvised comedy sketch, in which they know nothing beyond the costumes they have been given, and greeted by the line 'Thank God you're here!'. They must improvise their way through the sketch with the other actors onstage until a judge sounds a horn. The guest proclaimed the winner by judge Dave Foley takes home a cheap trophy -- and, of course, bragging rights. Based on the Australian series of the same name.

Each episode involves performers walking through a door into an unknown situation, greeted by the line "Thank God you're here!". They then had to improvise their way through the scene. At the end of each episode a winner was announced.