This paper discusses the #BlackProtest mobilization among Polish migrant women living in four European cities. The #BlackProtest is the name of the most impressive women’s rights protest in Poland’s recent history. The main research question explored in this study was what the act of solidarity, demonstrated in organizing the #BlackProtest internationally, meant for its organizers. The analysis of the reasons behind the transnational #BlackProtest organizing revealed that it is insufficient to talk about #BlackProtest mobilization only in terms of transnational activism. The theoretical framework of the study needed to be expanded from social movements to contemporary diasporas and the discussion demonstrated how through a process of identities, heterogeneity and boundaries’ negotiations a feminist diaspora was formed. Social movements’ theories, explaining the role of connective leadership, discursive opportunity structures and emotions in social mobilization helped to demonstrate how this media-driven mobilization initiated the emergence of a transnational, feminist diaspora.