Positive LGBT+ content in educational materials promotes a diverse and inclusive school environment for all students, particularly LGBT+. However, worldwide evidence shows that textbooks underrepresent LGBT+ issue. A possible explanation for this pattern is that most study topics do not lend themselves for issues related to sexuality and gender. We interrogate this argument by examining the representation of all sexual orientation, gender identity, and expression (SOGIE) in 36 state-approved history textbooks for high school in Israel. Utilizing an original standardized coding protocol, we compare representation of queer and hetero-cisgender content. Our findings reveal that textbooks include multiple references to SOGIE across various thematic contexts, yet these are almost exclusively limited to heterosexuality and cisgender persons, while queer sexualities and expressions are marginalized or excluded. We discuss the implications of these problematic patterns for school climate and offer recommendations for incorporating diverse SOGIE content in different study topics in history classes.