This study shares the experiences and outcomes of teaching about gender diversity in an elementary school classroom. It outlines how an urban public school teacher included discussions of transgender and gender-nonconforming people within the curriculum and documents the ways in which her students responded to those lessons. By making discussions of gender diversity a recurring theme in the curriculum, students learned to question restrictive social systems, think more inclusively about gender expression and identity, and apply this knowledge to other experiences. The students' responses to these lessons indicate that elementary school-aged children are ready for such an inclusive curriculum.