Dunsmore is a hamlet in the parish of Ellesborough, in Buckinghamshire, England. It is located on the hilltop of one of the Chiltern Hills, about 2 miles south of Wendover. It is one of the remotest places in the whole of Buckinghamshire, accessible only by two steep, single-track hillside lanes.

The place name is Anglo Saxon in origin, and means literally Dunna's moor.

Today the village is extremely picturesque, surrounded on all sides by Forestry Commission land. However due to its location it is regularly cut off because of bad weather or bad road conditions, and retains its small community atmosphere. A central feature of the hamlet is the village pond.

There are other English places called Dunsmore.