Castle Ashby is a village and civil parish in the West Northamptonshire unitary authority area of Northamptonshire, England. At the 2011 Census, the population of the parish (including Chadstone) was 111.

Historically, the village was set up to service the needs of Castle Ashby House, the seat of the Marquess of Northampton. The village has one small pub-hotel, The Falcon. The village contains many houses rebuilt from the 1860s onwards. These include work by the architect E.F. Law of Northampton, whose work can also be seen nearby at Horton Church. The castle is the result of a licence obtained in 1306, for Walter Langton, Bishop of Coventry, to castellate his mansion in the village of Ashby.

The village's name means 'Ash-tree farm/settlement'. There was a castle here, later replaced by the Elizabethan mansion.

• Compton Wynyates

• Pevsner, Nikolaus; Cherry, Bridget (1973) [1961]. Northamptonshire. The Buildings of England. Harmondsworth: Penguin Books. pp. 136–145. ISBN 0-14-071022-1.
• Turner, Roger (1999). Capability Brown and the Eighteenth Century English Landscape (2nd ed.). Chichester: Phillimore. pp. 112–114.

Media related to Castle Ashby at Wikimedia Commons

• Castle Ashby Cricket Club
• 1999 Oil Painting of Castle Ashby
• Castle Ashby Gardens website