Geilston Bay High School was a government co-educational comprehensive secondary school located in Geilston Bay, a suburb of Hobart, Tasmania, Australia.

Geilston Bay High School was opened on 9 February 1972 as the then Municipality of Clarence was enjoying a boom in residential expansion.

However, prior to the Tasman Bridge disaster in 1975, there were few facilities located on the eastern shore of the Derwent River.

The severing of the bridge made local authorities realise the need for localised services in areas of commerce, health care and education.

[1] Towards the head of the Bay, the (former) school playing fields cover what was once the Geilston Bay fossil site, which yielded fossil plants and animal bones in the nineteenth century of Late Oligocene (or possible early Miocene) age, including mammals that at one time were the earliest known from Australia.