This paper documents a significant association between the exposure of an individual or area to the UK government’s austerity-induced welfare reforms begun in 2010, and the following: the subsequent rise in support for the UK Independence Party, an important correlate of Leave support in the 2016 UK referendum on European Union membership; broader individual-level measures of political dissatisfaction; and direct measures of support for Leave. Leveraging data from all UK electoral contests since 2000, along with detailed, individual-level panel data, the findings suggest that the EU referendum could have resulted in a Remain victory had it not been for austerity. (JEL D72, F15, F60, H53, I38)