Medmenham is a village in Buckinghamshire, England. It is located on the River Thames, about three and a half miles southwest of Marlow, three miles east of Henley-on-Thames.

The village name is Anglo Saxon in origin, and means 'middle-sized homestead'. It was recorded in the Domesday Book of 1086 as Medmeham.

There was a Cistercian abbey founded in Medmenham in the 12th century, under the ownership of Woburn Abbey, though it was not officially recognised by royal charter until 1200. In 1547 at the Dissolution of the Monasteries the abbey was seized and given to the Moore family, and then sold privately to the Duffields. It was while in the possession of the Duffields that the abbey became infamous as the location of The Hellfire Club.

In 1755, when Sir Francis Dashwood acquired the ruins of the ancient abbey from the Duffield family he and John Montagu, 4th Earl of Sandwich attended a church service at St Peter's church in Medmenham where Sandwich let loose a small monkey into the church. The regular devotees fled in horror, sure that Satan himself had invaded their place of worship.

Today the abbey remains in ruins and is not open to the public. Medmenham, however, is a prosperous village on the banks of the Thames attractive with many executives who work in London and the nearby towns of Maidenhead and Reading.