Guildford (/ˈɡɪlfərd/ ) is a town in west Surrey, England, around 27 mi (43 km) southwest 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 151,359 inhabitants in 2024. Its name is thought to derive from a crossing of the River Wey, a tributary of the River Thames, that flows through the town centre.
The earliest evidence of human activity in the area is from the Mesolithic and Guildford is mentioned in the will of Alfred the Great from c. 880. The exact location of the main Anglo-Saxon settlement is unclear and the current site of the modern town centre may not have been occupied until the early 11th century. Following the Norman Conquest, a motte-and-bailey castle was constructed; which was developed into a royal residence by Henry III. During the late Middle Ages, Guildford prospered as a result of the wool trade and the town was granted a charter of incorporation by Henry VII in 1488.