Men's participation is essential to achieving gender equality. This study addresses research gaps in the under-studied area of men's participation in gender equality activism. We demonstrate, among an online sample of US men, (a) a strong, independent association (=.60) between degree of feminist self-identification and reported activism for gender equality and (b) the importance of survey language in assessing activism, with men being more likely to report activism when the term feminist', or related terms, is not used. The positive association between labelling and activism replicates in men a pattern consistently observed in women, and challenges the notion that men cannot be feminists. We also randomly assigned participants to report their degree of feminist identification either before or after reporting their level of activism. Whether feminist identification was reported first or last had no effect on activism rates. Overall, in spite of study manipulations (i.e. (a) modifications to scale language and (b) identity priming), activism rates remained low. Finally, an ancillary analysis demonstrated that feminist identification substantially mediated the association between sexual minority status and reported activism. Practical implications suggest the need to target stigma towards feminism in men in order to increase self-identification and, ultimately, activism.