Cliveden (pronounced /ˈklɪvdən/) is an Italianate mansion and estate at Taplow, Buckinghamshire, England. Set on banks 40 metres (130 ft) above the River Thames, its grounds slope down to the river. The site has been home to an Earl, three Countesses, two Dukes, a Prince of Wales and the Viscounts Astor.

As home of Nancy Astor, the house was the meeting place of the Cliveden set of the 1920s and 1930s—a group of political intellectuals. Later, during the 1960s, it became the setting for key events of the notorious Profumo Affair. During the 1970s, it was occupied by Stanford University of California, which used it as an overseas campus. Today owned by the National Trust, the house is leased as a five-star hotel run by London & Regional Properties.

Cliveden means "valley among cliffs" and refers to the dene (valley) which cuts through part of the estate, east of the house. Cliveden has been spelled differently over the centuries, some of the variations being Cliffden, Clifden, Cliefden and Clyveden. The 375 acres (152 ha) gardens and woodlands are open to the public, together with parts of the house on certain days. There have been three houses on this site: the first, built in 1666, burned down in 1795 and the second house (1824) was also destroyed by fire, in 1849. The present Grade 1 listed house was built in 1851 by the architect Charles Barry for George Sutherland-Leveson-Gower, 2nd Duke of Sutherland.