One of the most powerful predictors of violent political conflict is proximate violence in space and time. This spatiotemporal pattern has been identified between countries as well as within them. What explains this clustering is less clear, and different studies point to different mechanisms. Focusing on sub-Saharan African states, we examine whether population attitudes may contribute to the spatial diffusion of political violence that is found at sub-national scales. In a quasi-experimental research design, using geo-referenced survey data of 18,508 respondents for 162 administrative units across 16 countries, paired with precisely geo-referenced conflict event data, we find that popular acceptance for the legitimacy of using physical violence in the survey is positively associated with subsequent conflict events. Furthermore, the combined effects of nearby violence and approval of violence is stronger than either condition alone, implying a diffusion effect. This relationship remains even after controlling for previous levels of conflict, meaning that the finding cannot be dismissed as merely reflecting a reverse causal effect. We also find some evidence that conflict events affect public opinion, implying a mutually reinforcing relationship between violence and general acceptance for using violence.