Background: High school staff can play a key role in supporting students with LGBTQ+ identities through informal strategies; however, more research is needed to understand how staff are employing these strategies. Methods: We conducted semi-structured interviews, collecting information on informal strategies used to support students identifying as LGBTQ+ from a diverse sample of 23 school staff from high schools across the United States. Results: Staff employed informal support strategies across social ecological levels: within the school community, staff interacted with parents/guardians of students and advocated for more inclusive policies. Within the classroom, staff created inclusive physical environments, implemented inclusive curricula, and employed bullying prevention strategies. Interpersonally, staff listened to and affirmed students and collaborated to employ support strategies. Intrapersonal qualities, including having a personal connection to the LGBTQ+ community and demonstrating open-mindedness, facilitated staff efforts to support students. Conclusions: Supporting staff in the implementation of the strategies we identified could foster more inclusive school environments, advancing equity for students identifying as LGBTQ+. [Members of the Coulter Lab Qualitative Team contributed to the writing of this article.]