Botleys Mansion is a Palladian mansion house in the south of Chertsey, Surrey, England. The house was built in the 1760s by builders funded by Joseph Mawbey and to designs by Kenton Couse. The elevated site once bore a 14th century manor house seized along with all the other manors of Chertsey from Chertsey Abbey, a very rich abbey, under Henry VIII's Dissolution of the Monasteries and today much of its land is owned by two hospitals, one public, one private and the local authority. The remaining mansion and the near park surrounding were used for some decades as a colony hospital and as a private care home. The building is owned and used by Bijou Wedding Venues Limited.
The history of the site is unclear. The building standing today was built in the 1760s as a replacement of an old manor. The mansion's ownership was transferred often throughout its history.
The Metropolitan Asylums Board was dissolved in 1930 and responsibility of caring for the mentally deficient was passed to the (local government) Councils.Surrey County Council decided set up new buildings to house patients while the mansion housed the hospital staff becoming designated from 1932 Botley's Park hospital, which specialised in patients with psychiatric disorders. The first section of the new hospital was opened on 24 June 1939 by Lady Henriques, wife of then chairman of the Council Sir Philip Henriques. In September of the same year, many of the hospital's patients were moved to Murray House in Ottershaw so that Botleys could receive wounded soldiers from the war. During this time, the mansion was adapted into a nurses' home.
In 1995, a fire severely damaged the building, and within two years, most of the hospital closed down.
Botleys Mansion is a Couse stone-built house in simple Palladian architecture without wings, surrounded by park land and iron gates. The stone came from quarries at Headington, Oxfordshire and Barrington, Cambridgeshire. It is a Grade II* listed building.