The Upright Citizens Brigade Theatre (shorter UCB Theatre) is an American improvisational theatre company and training center founded by the Upright Citizens Brigade troupe members Matt Besser, Amy Poehler, Ian Roberts and Matt Walsh. Members of the Upright Citizens Brigade originally trained with Del Close at Chicago's ImprovOlympic where they created their signature ASSSSCAT show, the success of which led to the troupe founding the UCB Theatre in New York City.