Politics in states where there exists an active and relevant regionalist movement take on a certain distinction. In addition to ideological positioning based on social and economic stances, centre-periphery issues add a third ideological dimension that needs to be acknowledged. Yet, rarely does electoral research give appropriate attention to these three independent ideological dimensions simultaneously. This paper examines the importance of the economic, social and centre-periphery ideological dimensions on vote choice in sub-national elections. Through a three-dimensional proximity model of voter-party congruence and using data from the Making Electoral Democracy Work project, this paper explores the impact that ideological distances between voters and political parties have had on recent electoral outcomes in two areas with distinct regionalist politics: Quebec and Catalonia. This study aims to not only contribute to the understanding of vote choice in regionalist states, but also refine how scholars ideologically place parties in such states.