From Trump's America to Putin's Russia, from climate change denial to corona denial, so-called post-truth politics are experiencing a global rise. How can we understand and explain this phenomenon? In the attempt to answer this question, this article advances two core claims. First, it suggests that post-truth politics is (despite its name) marked not only by the denial of claims to objective truth, but also by the naturalization of one specific truth claim: namely, the cynical belief that self-interests are behind all public discourse. Second, it locates the social sources of this dogmatic cynicism in the global expansion of neoliberal competition.