In the present contribution, we examine the link between societal crisis situations and belief in conspiracy theories. Contrary to common assumptions, belief in conspiracy theories has been prevalent throughout human history. We first illustrate historical incidents suggesting that societal crisis situations—defined as impactful and rapid societal change that calls established power structures, norms of conduct, or even the existence of specific people or groups into question—have stimulated belief in conspiracy theories. We then review the psychological literature to explain why this is the case. Evidence suggests that the aversive feelings that people experience when in crisis—fear, uncertainty, and the feeling of being out of control—stimulate a motivation to make sense of the situation, increasing the likelihood of perceiving conspiracies in social situations. We then explain that after being formed, conspiracy theories can become historical narratives that may spread through cultural transmission. We conclude that conspiracy theories originate particularly in crisis situations and may form the basis for how people subsequently remember and mentally represent a historical event.