Swan Island is a small, privately owned island in the River Thames at Twickenham, in the London Borough of Richmond upon Thames, London, England. It is situated on the Tideway about 3⁄4 mile (1.2 kilometres) downstream of Teddington Lock.
The island has a harbour which is run by the Port of London Authority. It also has a considerable amount of commercial activity on it in addition to residential mooring for boats. It is connected to the Twickenham bank by a small bridge, which is suitable for vehicles as well as foot traffic.
Coordinates: 51°26′21″N 00°19′52″W / 51.43917°N 0.33111°W