The chapter provides a review of the evidence base on whether, and if so in what contexts, inequality drives Islamist and extreme-right radicalisation. It is based on the outcomes of a Meta-Ethnographic Synthesis (MES) of qualitative findings and a Systematic Review (SR) of quantitative findings about inequality-radicalisation link. The findings of both reviews highlight the importance of multidimensionality of inequality, and perceived inequality specifically, as well as mutual relations between inequality and radicalisation. We stress the unique and complementary insights from both reviews in the context of possible recommendations for policy and decision makers, as well as future radicalisation studies.