This paper looks into the emergence and the evolution of Hong Kong nationalism in the context of party and contentious politics over the past years. Identifying on the one hand effects of polarization and fragmentation in the party system, and on the other hand a broadening of identity claims, this paper traces the process through which Hong Kong nationalism evolved from ethnicist movements into a more multidimensional and predominantly civic ideology. It argues firstly that the institutionalization of these movements into political parties in response to the failure of the democratization process in 2014 required the adoption of more nuanced and pragmatic platforms allowing them to compete with pan-democratic parties, bringing about a maturation of Hong Kong identity claims as a whole. Secondly, the government’s crackdown on nationalist parties has forced their return to street politics, allowing the consolidation of a multi-level alliance between pan-democratic and more radical forces against Beijing’s increasing grip and the Hong Kong government’s mounting authoritarianism.