Efforts to engage men and boys to prevent gender-based violence (GBV) have proliferated rapidly throughout much of the world. These efforts can be seen in marked expansion of community-based prevention programming, as well as in policy support for such involvement. Many of the most innovative, best developed programs and most rigorously evaluated have grown internationally outside of North America. In this special issue, we offer a compilation of some of the exciting work underway to conceptualize, create, implement, and evaluate these rapidly developing efforts around the world. Authors address the theoretical foundations of this work and present some examples of how programs are being implemented, including models developed in the Global South adapted for the Global North. Authors also address the tensions and ongoing concerns that accompany these burgeoning attempts to include men and boys in the effort to end GBV.