This article considers the resurgence of interest in feminist solidarity in theory and practice in the contemporary moment in the United States and UK. What does feminist solidarity mean, what forms is it taking, and how might it proliferate? We begin by mapping the changing inflections of solidarity in recent feminist cultural theory, highlighting the range of theoretical components, investments and emphases. Next, we consider the various forms of solidarity presented and created by the Women’s March and the Women’s Strike, analysing the differences in terms of the extent of their reach and their political economy. We argue that both phenomena can be understood as reactions to, firstly, several decades of neoliberal impoverishment, which have now exposed neoliberal iterations of feminism as fundamentally inadequate; and secondly, and relatedly, the arrival of misogynistic and reactionary forms of nationalism. Finally, we show that different approaches to feminist solidarity, as well as an expansion of alliances, are necessary in order to extend contemporary feminism as an effective and large‐scale project. We therefore argue that feminist solidarity needs to retain its genealogical roots in left politics whilst being as plural as possible in practice.