Coldeast is a former manor house and former psychiatric hospital between Park Gate and Sarisbury in Hampshire, England. The house is used today as a wedding and conference venue and much of the former grounds are being redeveloped for housing and the construction of a new leisure centre.
Coldeast is situated in the Park Gate ward of Fareham Borough, between Park Gate itself and Sarisbury. The site is a little over 0.6 miles (0.97 km) northeast of the River Hamble.
Previously part of the manors of Titchfield and Swanwick, Cold East Farm was located on the site of today's manor house in 1765. In 1837 it was owned by Robert Cawte and occupied by William Cawte, but a few years later was in the hands of the Hornby family.
It was occupied by horse trader Arthur Hornby by the 1840s and the 1851 census shows that three staff lived there with him. The Hornby family were wealthy local landowners, and extended the house and grounds during their tenure, adding stables, dungeon, outhouses, two lodge houses and carriage drives lined by avenues of trees, all of which appear on the Ordnance Survey map of 1868. As well as Coldeast the family owned Hook House near Warsash, where William Hornby lived until his death in 1869. Arthur Hornby inherited the house and decided to move there, selling Coldeast, which was described as his "favourite abode in the sales notice. The notice described a moderate sized house and listed pleasure grounds, kitchen gardens, vineries, parkland, heathland and sea views among the assets on the 150-acre (61 ha) estate.
Nathaniel and Emma Montefiore bought the estate in 1870 and continued to develop it, adding glasshouses and formalising the grounds, reflected on the Ordnance Survey maps of 1897 and 1909. Their son, Claude Montefiore, spent part of his childhood there in the early 20th century. The estate was sold again in 1924 to Hampshire County Council by a Mr L G Montefiore. The council added a further 170 acres (69 ha) to the estate and converted it to use as a psychiatric hospital, adding a boundary fence and ditch alongside the main road and building additional patient accommodation on the site.