This thesis looks at the success of radical right parties in Western Europe through the perspective of welfare politics, by examining parties and voters in a comparative and mixed method perspective. I argue that purely socio-cultural or socio-economic accounts of the radical right success face several theoretical and empirical shortcomings. Focusing on the conflict dimension of welfare politics - who gets what, when and how in terms of social benefits – constitutes a novel approach to explain these parties’ and voters’ political preferences. Relying on different theories of the political sociology of the welfare state, I put forward the protection and exclusion hypotheses, which have implications at the party and at the voter levels. On the demand side, the precarization sub-hypothesis expects that economically insecure voters are likely to support radical right parties who offer them an alternative to mainstream parties. The scapegoating sub-hypothesis expect that voters who feel that core normative beliefs of the moral economy of the welfare state are being violated by individuals or outgroups should support the radical right because it fosters an exclusive conception of welfare politics. On the supply side, the programmatic shift sub-hypothesis expects that radical right parties turn their back on their initial ‘winning formula’ (which entailed retrenchment of welfare institutions) in order to adopt protective welfare preferences that match their constituents’ economic insecurity. The exclusive solidarity sub-hypothesis expects that radical right parties frame their welfare preference in terms of group inclusion and exclusion. I find that economic insecurity and welfare specific attitudes (welfare populism, welfare chauvinism, welfare limitation and egalitarianism) underlie voters’ support for radical right parties. Conversely, some – but not all – West European radical right parties have adapted their welfare preferences towards protective welfare policies in order to match their constituents’ concerns. However, all radical right parties put forward an exclusive conception of solidarity. These findings contribute to a finer-grained understanding of the electoral of radical right parties in Western Europe, and also open a broader research agenda for the better inclusion of welfare politics in electoral studies.