Galston High School is a government-funded co-educational comprehensive secondary day school, located in Galston, a suburb in the Hills District of Sydney, New South Wales, Australia.

The school site was previously owned by James David Waddell.^{[citation needed]} A cottage was built in 1867, now known as Waddell Cottage.^[1] Waddell lived in the cottage until 1969, by when the house and orchard were in a bad state of repair. Waddell had refused to put in running water or have the electricity connected. Because he hadn't paid his taxes, the land was resumed by the government as it was thought to be an ideal location for a high school.^[1]

Galston High School officially began in 1972, although the first classes were taught at Baulkham Hills High School.^[2] In 1974, the school's buildings opened on the current site and were added to until its final completion in 1982.^{[citation needed]} The first HSC class to graduate was in 1977.

In the early hours of 19 May 2014, Galston High School's library caught fire. This occurred from some technical difficulties in the electric wire systems.^[3]

This article's list of alumni may not follow Wikipedia's verifiability policy. (April 2022)

• Adam Berry, footballer
• Adam Wilkinson, talent manager
• Aden Young, actor

• Elena Duggan, winner of MasterChef Australia 2016

• List of government schools in New South Wales
• Education in Australia