Baulkham Hills High School was established in 1971 as a public comprehensive high school. It was officially opened on 23 March 1974 by the then Governor, Sir Roden Cutler. For the first year, students and teachers at the school were relocated to nearby Castle Hill High School whilst Baulkham Hills High School was still under construction. The school's first selective cohort was in 1990, with all grades being selective by 1995.
