Although Northcote High School was established as a co-educational school, it became a boys' school after 1928 when Preston Girls High School was established. Martin Hansen, the then Chief Inspector of Secondary Education, was convinced high schools should be segregated by gender after a tour of schools in the US and UK. In the 1980s Northcote High School again began to enrol girls in response to community pressure, officially moving to co-education in 1989. In 2018 there were approximately 920 boys and 829 girls enrolled.