It is north-west of Hughenden, on the ridge of one of the Chiltern Hills, and is adjacent to the village of Walter's Ash.

Naphill borders the ancient parishes of Bradenham, North Dean, and West Wycombe.

Whilst a village in its own right, it is part of the Parish of Hughenden, and is located around the former border between two ancient British tribes, the Catuvellauni and the Atrebates.

Walter's Ash in Naphill is the location of RAF Strike Command, which contains a nuclear bunker built on National Trust land in 1983–1985.

The Common contains evidence of an industrial background, including medieval iron smelting.