The existing research on contextual sources of support for populist parties has revolved around two factors: the unemployment rate and the size of immigrant groups. Conceived as residential characteristics, observation of these factors has been seen to increase support for radical parties in Western European countries. We identify different contextual (non-individual) drivers of support for populist parties in the post-communist Czech Republic (Czechia). Based on a large sample of voters ( n = 23,734), we identify the (contextual) effect of economic hardship and demographic decline on support for populist parties. We interpret these results as supporting the theory of regional peripheralization. This peripheralization has been identified to be particularly strong in the post-communist countries of Central and Eastern Europe, and has widened regional socio-economic disparities in this region. We show how these processes have affected voting behaviour and support for political parties. In a second step, we use a sample from eastern Germany ( n = 524) to test whether peripheralization affects support for populist parties in other post-communist regions. The results confirm the hypothesis also in the case of east Germany. Our study contributes to the debate by pointing out a novel mechanism that leads to increased support for radical and moderate populist parties.