Gender and sexual minority students experience higher levels of victimization in schools, making teacher intervention important. We examined how school climate, educator experiences (prior training, personal experience with harassment), and educator attitudes (homophobia, transgender knowledge) were associated with intention to intervene in cissexist and heterosexist victimization using two samples: pre-service teachers (n = 416) and in-service teachers (n = 931). For in-service teachers, higher transgender knowledge, lower homophobia, and personal harassment experience were associated with greater intervention intentions. Prior training was associated with greater transgender knowledge and greater intervention intentions. For the pre-service teachers, lower homophobia was associated with greater intervention intentions. In both samples, more school climate barriers were associated with greater transgender knowledge and lower homophobia. Results highlight the importance of ensuring teachers receive initial and continued education on diverse gender and sexual identities