At first glance, humor and politics may appear oppositional. Politics is often understood as serious, important, and grave, while humor is perceived as lighthearted and frivolous. Beneath the surface, however, it is evident that humor and politics are actually inextricably linked and have been throughout political history. This paper interrogates the tensions between humor and seriousness, importance and frivolity, and legitimate and dismissible to examine the manifestations of humor in social movement protest. I discuss how humor is used as a communicative and emotional strategy for social movement activists and organizations and focus on two constellations of movement humor: humor directed outside the group in the forms of tactics and frames, which I term external humor, and the role of humor in leadership, collective identity, and emotional labor, termed internal humor. To illustrate the role of humor in protest, I integrate examples from scholarly research, media depictions, and participant observation data to provide examples of how humor is manifest as an external tactic, social movement frame, and its potential role in strengthening ties to leadership and collective identity. The essay concludes by highlighting some potential paths for future study about the relationship between humor, ideology, identity, and power.