"Butt Out" is the thirteenth episode of the seventh season of the American animated television series, South Park, and is the 109th episode overall. It first aired on Comedy Central in the United States on December 3, 2003.

In the episode, representatives from the anti-smoking campaign rap about the dangers of smoking for the children of South Park. For fear of growing up to be giant nerds, the boys decide to take up the nasty habit.

The episode pokes fun at the formulaic storyline of some South Park episodes (including the movie), which start with the boys getting themselves in trouble and inciting a controversy between the townsfolk and a national interest group (or a major catastrophe) while trying to avoid punishments, subsequently learning a lesson from this conflict.