Andersey Island is a large island in the River Thames in England near Abingdon, Oxfordshire on the reach above Culham Lock.
The island is created by a division in the stream of the river between the main navigation channel and the Swift Ditch backwater. The Swift Ditch used to be the main course of the Thames until navigation was diverted to Abingdon. Comprising some 273 acres (1.10 km2), the island is one of the largest islands on the Thames.
The island of Andersey was the site of a royal residence as early as Anglo-Saxon times, and was taken over by William I. The site was handed over to the Abbot of Abingdon in about 1100 and the buildings fell to ruin. Most of the island is open land with poplars and willows, but it also contains a football club, a cricket club, a leisure facility, barns and cottages.
Coordinates: 51°40′01″N 1°16′12″W / 51.667°N 1.270°W