Bonnet Bay is a suburb in southern Sydney, in the state of New South Wales, Australia that is located 29 kilometres (18 mi) south of the Sydney central business district in the local government area of the Sutherland Shire. Its postcode is 2226, which it shares with neighbouring Jannali and Como. Bonnet Bay is located on the eastern bank of the Woronora River, which flows north into the Georges River.