The village is on the north bank of the River Thames about 3.5 miles (5.6 km) northwest of Reading. The only road access is by a narrow and steep lane from Trench Green on the rural road from Caversham to Goring Heath and Goring on Thames. Despite the fact that Mapledurham village is closer, as the crow flies, to central Reading than some of that town's suburbs, it remains a remote and rural location.
The civil parish of Mapledurham covers a considerably larger area than the village itself, and includes the even smaller settlements of Trench Green and Chazey Heath in the Chiltern Hills above the village. It is bordered to the west by the parish of Whitchurch-on-Thames and Goring Heath, to the north by the parish of Kidmore End (until 1894 part of Caversham), to the east by the Reading suburb of Caversham, and to the south by the River Thames. In the 2011 UK census, Mapledurham civil parish had a population of 317, an increase of 37 over the previous census in 2001.
Mapledurham House, the country house that is the headquarters of the Mapledurham estate, is one of the largest Elizabethan houses in Oxfordshire. The Mapledurham estate owns much of the village and parish. It also includes the Mapledurham Watermill, a historic and still operational watermill on the River Thames.