On 8 February 1910, 79 students, together with eight teachers and an acting headmaster, began classes in a couple of disused rooms at the Gordon Institute of TAFE.

The current site was selected in East Geelong, on the southwest corner of Eastern Park, and the new school, to accommodate 450 students, was completed in August 1915.

During 2018, rooms 3–8 were demolished to make way for the new Year 7 courtyard, the Kroger Wing was refurbished, including the addition of a second storey.

[5] The language was introduced as a replacement for Korean as a LOTE subject, which had been taught since the mid-1990s but was removed from the school curriculum at the end of 2006.

Geelong High school offers a number of senior study pathways for Year 10, 11 and 12 students, including Victorian Certificate of Education (VCE), Victorian Certificate of Applied Learning (VCAL) and Vocational Education and Training (VET).

VET, as part of the VCE program, combines a student's general studies with vocational ones in Year 10, 11 or 12.

The aim is to give participating students an advantage when applying for full-time apprenticeships in trade areas.

[7] During 1994, the school purchased some former church buildings on the corner of Ryrie and Garden Streets, and converted them into what is now the Shenton Performing Arts Centre.

[8] This complex hosts a fully equipped theatre, in addition to music classrooms, dance studios and performance spaces.