Men constitute the majority of violent extremists and terrorists, yet academic research in the field has largely overlooked the role of masculinity. This article explores how the relationship between masculinity and political and religious violent activism has been understood in a small but emerging field of critical men and masculinities studies on Jihadist, far-right, and left-wing extremism. Through a scoping review of academic literature published 2000–2022, it examines how masculinity intersects with radicalization processes, extremist ideologies, and political and religious violence across these movements in Western societies. It outlines the main contributions of this literature, including that despite their differing political views, extremist groups share common ideals of performing masculinity through street violence and militarized activism. However, while left-wing movements endorse gender equality, both far- right and Jihadist extremists contend that masculinity is threatened by feminism. These latter environments hold misogynistic views central to their ideologies while simultaneously accusing others of sexism and misogyny to justify their violent activism. The discussed literature also suggests that young men often become radicalized not primarily for ideological reasons, but as ways to prove their masculinity and deal with their experienced social and economic marginalization. Finally, the article proposes that the concept of “remasculinization” helps us understand how violent extremism may serve two purposes simultaneously: as a tool for individuals attempting to meet masculinity standards, and as a means for broader political projects aimed at maintaining male supremacy.