Guildford is a town in west Surrey, England, around 27 mi (43 km) south-west of central London. As of the 2011 census, the town had a population of about 77,000; it is the seat of the wider Borough of Guildford, which had around 145,673 inhabitants in 2022. The name Guildford is thought to derive from a crossing of the River Wey, a tributary of the River Thames that flows through the town centre.