This article argues that populism in power translates into a greater tendency to politicize foreign policy, in the sense of defining and articulating foreign policy preferences in opposition to political predecessors, using foreign policy as an instrument and ground to battle political opponents, and over-prioritizing domestic incentives and considerations over external ones. Paradoxically, compared to other classical determinants of foreign policy, how populism relates to domestic political competition has received scant attention. Yet, populist actors’ strategies in dealing with political opposition are at the same time distinctive and consequential. This article advances a typological theoretical framework shedding light on the pathways, patterns, and implications of populist politicization, which it illustrates empirically with reference to the case of Poland.