Millfield Wood is a 9.5-hectare (23-acre) biological Site of Special Scientific Interest north of High Wycombe in Buckinghamshire.

It is owned and managed by the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust, and it is in the Chilterns Areas of Outstanding Natural Beauty.

[1][2] The site was owned in the late nineteenth century by Benjamin Disraeli, and the woodland is much older.

It is semi-natural beech woodland on chalk, which is an unusual habitat, and it also has considerable wych elm.

There are a number of badger setts and a varied invertebrate fauna.