Research has demonstrated supportive teachers' importance in the success and safety of lesbian, gay, bisexual, transgender, and queer (LGBTQ) students. However, few researchers study the degrees to which sociocultural factors and actors shape teachers' efforts to build LGBTQ-positive classrooms. This article is part of a larger longitudinal study that examined novice English teachers' attempts to build LGBTQ teacher ally identities. Participant narratives suggested that school-based cultural norms, including understandings of gender and standardized testing, heavily informed the ways in which a secondary English teacher was able to be a teacher ally.