Willen is a district of Milton Keynes, England and is also one of the ancient villages of Buckinghamshire to have been included in the designated area of the New City in 1967.

Willen is not recorded by name in the Domesday Survey, but it can be identified with the 4 hides 1 virgate assessed under Caldecote, part of the neighbouring parish of Moulsoe, and held under the Count of Mortain by Alvered.

[4][5] The parish church (1680), was designed by the architect and physicist Robert Hooke and is a classic of the early English Baroque period.

[9] One of the more important features of the district is a large balancing lake on the River Ouzel, designed to capture flash floods lest they cause problems down stream.

The south lake is for leisure use, with a full watersports and boat hire centre, as well as inflatable aqua park and wakeboarding facility.