This essay presents “fattening austerity” as a new conceptual framework that will enable a collective resistance to austerity politics and fat oppression. Austerity and fatphobia have not, to our knowledge, been analyzed in tandem. But the discourses that uphold both punitive austerity measures and the pathologization of fat people’s bodies are deeply imbricated. Austerity and anti-fat stigma each invoke a language of crisis to authorize social practices that inflict hunger and bodily injury upon people who are fat and/or poor. In addition, anti-‘obesity’ rhetoric and pro-austerity arguments each utilize the neoliberal values of “personal responsibility” and corporeal “choice” to further marginalize people who are poor, fat, or both. We argue that it is incumbent upon the political Left—which thus far has been remiss in challenging the anti-fat prejudice that often animates its own movements—to make fat justice a central part of its critique of austerity.