In the context of both the financial crisis and the crisis of European migration politics, the notion of solidarity has gained renewed prominence and – as this book argues – its practice has become increasingly contentious. Intersecting crises have sharpened social and political polarization and have contracted simultaneously the space for migrant and minority rights as well as the rights around political dissent. Building upon social movement and migration studies, this book maps the two sides of ‘contentious solidarity’: a shrinking civic space and its contestation by civil society. The book thereby unfolds the variety of repressive means (physical, legal, administrative and discursive) employed by governmental and non-governmental bodies against migrant solidarity, but also looks at how civil society organizations react to these restrictions through at times moderation and at times increasing contention. The diagnosis of ‘contentious solidarity’ is located within two broader trends affecting the relationship between the state and civil society in a neoliberal context in general and since the financial crisis in particular.