Greythorn High School was a state-run high school (years 7-12) in the suburb of Balwyn North, in Melbourne, Victoria, Australia. The school was established in February 1958, meeting for the first time at Balwyn High School as the new building at Greythorn Road was not completed at that time. After three days, the 81 students and 5 teachers transferred to temporary premises at St Silas Hall and the Scout Hall at Macleay Park. The school moved to the permanent Greythorn Road site in June 1958. The school was officially opened on Saturday 4 June 1960 by the Minister for Education, J. S. Bloomfield, MLA.