Thornbury High School is a government-funded co-educational secondary day school, located in, Victoria, Australia. It is situated at the eastern end of the City of Darebin, on Dundas Street & Collins Street, Thornbury. The school caters to a cohort of diverse students, and has a long history of celebrating multiculturalism and cultural inclusion through its engagement with initiatives such as Harmony Day, and the Wirrapanda Foundation. The school is also a strong promoter of the performing arts through its involvement with the Malthouse Theatre's "Suitcase Series", student radio station SYN FM (originating at the school as 3TD FM), and Class TV, a student-produced television program airing on Channel 31, winner of two Antenna Awards for Best Youth Program.

Notable alumni