Walton-on-Thames, known locally as Walton, is a market town on the south bank of the Thames in northwest Surrey, England. It is in the Borough of Elmbridge, about 15 mi southwest of central London. Walton forms part of the Greater London Built-up Area, sits within the KT postcode, and is served by a wide range of transport links. According to the 2011 Census, the town has a total population of 22,834.