Male supremacist groups and ideas are an increasing threat to the positive development of young people, including college students. This study examines actions students proposed taking when presented with a scenario in which a male classmate displayed warning signs of having been exposed to male supremacist ideas online. We conducted 16 semi-structured interviews with undergraduate students involved in sexual violence prevention efforts on college campuses, who acted as key informants. Participants were ages 18 to 23, female or non-binary, and attended geographically diverse U.S. colleges. More than 50% held marginalized racial and/or ethnic identities, and more than 50% held LGBTQ+ identities. We analyzed students’ responses using critical thematic analysis informed by social justice youth development and antifascist violence prevention. Students suggested direct intervention strategies to encourage change in the hypothetical classmate, and identified peers, faculty, and staff who they would talk to about the warning signs. Students also identified barriers to intervention, including personal safety risks and wanting proof of harm. Findings indicate the need for: institutional resources for options other than peer bystander intervention that can promote individual change; support for students to assess their safety when choosing intervention strategies; and antifascist community-building.