Sunbury Lock Ait is the ait (island) in the River Thames in England adjacent to Sunbury Lock between Walton-on-Thames, and Sunbury-on-Thames, Surrey. It is unpopulated, but accessible by a footbridge over the lock cut from a wide section of the Thames Path towpath on the southern bank as well as walkways on the lock gates. Thirdly, a walkway links to Wheatley's Ait upstream, across the weir, but this is closed to the public.