ISSUE ADDRESSED: To describe the need for high school sleep education from the perspective of undergraduate university students. METHODS: Undergraduate students who completed an online course on sleep and circadian health were surveyed 6 months after course completion. Students were asked whether a similar course would have benefited them as high school students, and about the need for sleep education in high schools. Thematic analysis of this qualitative data was carried out. RESULTS: Eighty-nine students who had attended 71 unique high schools provided responses. Eight-one per cent thought they would have benefitted from a similar course during high school and identified domains of sleep knowledge particularly relevant to high school students. They cited environmental barriers to healthy sleep present during high school and believed that sleep education could improve students' lifestyle, sleep and performance. Nineteen per cent of students said they would not have benefited, because they perceived sleeping patterns during high school to be nonmodifiable or believed that previous sleep education was sufficient. Of the respondents who did not think students would benefit, 53% would still tell their high school principal that there was a need for sleep education. CONCLUSIONS: The findings support the need for engaging sleep education for high school students. Future studies should examine the perspectives of students in high school directly, rather than undergraduate students who have already shown an interest in sleep health. SO WHAT?: Sleep health is missing from the Australian school curriculum. Online courses may be an engaging method of promoting sleep and circadian health to high school students.