Few studies have investigated school-based, positive development for lesbian, gay, bisexual, and queer (LGBQ) youth, despite knowledge of their heightened negative school experiences compared to heterosexual youth (e.g., school victimization). This study examines associations among participation in Gay-Straight Alliance (GSA)–related social justice activities, GSA presence, and GSA membership with victimization based on sexual orientation and school-based well-being (i.e., school safety, school belongingness, grade point average [GPA]) and future plans to vote. Using data from the Preventing School Harassment Study, a survey of 230 LGBQ students in 7th through 12th grades, the study finds that participation in GSA-related social justice activities and the presence of a GSA are positively associated with school belongingness and GPA. GSA membership is also positively associated with school belongingness. However, moderation analyses suggest that the positive benefits of GSA-related social justice involvement and the presence of a GSA dissipate at high levels of school victimization. Implications for schools are discussed.