Gymea Bay is located 27 kilometers south of the Sydney central business district; it is in the local government area of the Sutherland Shire. Gymea Bay shares its 2227 postcode with the adjacent suburb of Gymea. Gymea gets its name from both a flower and its position on the Port Hacking River. The Gymea lily is a tall 6 meter perennial that was once prevalent in the area. The lily was named by the local Eora people and it was the inspiration behind neighbouring Gymea’s name.
Due to development in the area many of the lilies have been killed off, however they can be still found a few kilometers south in the Royal National Park. The bay comes from the small bay on the north shore of the Port Hacking Estuary also known as the Port Hacking River. Gymea Bay is a mostly residential area with a small shopping strip on Gymea Bay Road.