Today, populism has gradually become one of the most talked about, most studied phenomena, both within and beyond academia. Most studies of populism focus on its conceptualisation, operationalisation, measurement or its outcomes. However, adding to the growing empirical analysis of populism, we propose to study populism as a regional-level phenomenon and explain regional patterns of variation in the populist demand. To do so, we develop a series of theoretical arguments from, which we subsequently test empirically. Specifically, we argue that higher levels of regional populism demand are associated with (i) economic hardship, (ii) strong institutional autonomy, (iii) strong territorial identity, and (iv) greater distance to elites. We construct a populist index for 143 regions across nine countries and combine this with a unique and rich regional database. While we find that populism holds distinct regional patterns and there is support for classic predictors like economic hardship, we are also able to provide some unique insights into the regional foundations of populism, most notably the predictive power of regional identity and the distance to national elites.