During World War II, Nuneham House and land around it was requisitioned by the Ministry of Defence and became RAF Nuneham Park. It was a P.R.I.U. or photographic reconnaissance interpretation unit. Examining the photographs taken by aircraft from RAF Benson and other airfields over enemy territory, were not only RAF officers but also small contingents from the Army, Royal Navy and the USAAF. Nissen huts and other, larger, buildings were erected adjacent to the mansion, including a camp cinema which villagers were welcome to attend. The RAF Station continued after the war in the same role until the mid fifties, when the added buildings and roadways were demolished and the estate handed back to the Harcourt family, who sold it to Oxford University.
The Harcourt Arboretum, part of the tree and plant collection of Oxford University's Oxford Botanic Garden, occupies part of what were the grounds of Nuneham House. The village is also home to the Bodleian Library's Nuneham Courtenay Book Repository.