While educators, curriculum authors and policy makers alike are influenced by assumptions about parents’ dis/approval of gender and sexuality diversity, both generally, as well as specifically in relation to this topic’s appropriateness for K-12 classrooms, little empirical data is available to support these assumptions. What data does exist suggests that parents generally support the implementation of a comprehensive sexuality curriculum, inclusive of same-sex attraction, and view sexuality education as a school-parent partnership. Surveying a sample of Australian parents of children attending a government (public) school (N = 2093), whose responses were weighted to produce nationally representative estimates, this study sought to expand on previous findings by exploring the complexities of parents’ attitudes in relation to gender and sexuality diversity and its place within relationships and sexual health education. This paper provides a descriptive overview of parents’ ideas about the purpose of relationships and sexual health education and their views on the importance of including gender and sexuality diversity-inclusive content within related curriculum areas. Notably, over 80% of parents supported the inclusion of gender and sexuality diversity-inclusive relationships and sexual health education topics across primary and secondary government schools.