Political parties have been the subject of a recent resurgent interest among political philosophers, with prominent contributions spanning liberal to socialist literatures arguing for a more positive appraisal of the role of parties in the operation of democratic representation and public deliberation. In this article, I argue for a similar re-evaluation of the role of political parties within contemporary republicanism. Contemporary republicanism displays a wariness of political parties. In Philip Pettit’s paradigmatic account of republican democracy, rare mentions of political parties often stress their tendency to lead to factionalism or corruption. Others working in the republican tradition such as Richard Bellamy and Ian Shapiro provide more extended discussion of the role of parties, but limit their theoretical function to enabling electoral competition. I argue that political parties play a far more significant role in promoting non-domination than this. In addition to enabling electoral competition, I show that political parties are also essential to the effective operation of two other components of republican democracy: contestation and interest-formation. I further argue that understanding political parties in these terms is compatible with republican democracy more generally, addressing the worry that parties will produce factional rather than common-good oriented public decisions.