Gay-Straight Alliances (GSAs) aspire to empower youth to address multiple systems of oppression, including those affecting transgender and racial/ethnic minority youth, yet there is little indication of factors contributing to youths' self-efficacy to do so. We examined individual and group factors predicting self-efficacy to address transgender and racial issues among 295 youth in 33 high school GSAs. Multilevel results indicated that level of GSA engagement, individual and collective involvement in transgender- and race-specific discussions, and in some cases intergroup friendships were associated with each form of self-efficacy. The association between GSA engagement and transgender self-efficacy was stronger for youth in GSAs with greater collective transgender-specific discussions. Associations with racial self-efficacy differed based on youths' race/ethnicity. Continued research needs to identify how GSAs and similar youth programs promote self-efficacy to address diversity issues. Impact and Implications: This study highlights the potential of diversity-focused youth settings such as Gay-Straight Alliances (GSAs) to empower youth to address discrimination and issues faced by minority populations. It advances GSA research by considering individual and group differences; and suggests that active involvement in peer discussions and being socialized around other members who collectively discuss such issues may benefit youth depending on the issue at stake.