Based on data from two latest waves of a countrywide longitudinal survey in the UK, this study examines the causal effect of the Brexit referendum on life satisfaction of the immigrant population. By adopting a quasi-experimental, triple-difference approach, we find that the referendum has a slight negative impact on life satisfaction of the native-born as well as recent immigrants originating from EU countries. However, the referendum has large, positive impacts on other immigrant groups. Among the younger population, a large increase in life satisfaction due to the referendum is found among recent non-EU immigrants, whereas no negative effect of the referendum is detected on other groups. Among the older population, the referendum greatly increases life satisfaction among established immigrants, and particularly those originating from EU countries.