Castlethorpe is a village and civil parish located in the unitary authority area of the City of Milton Keynes in Buckinghamshire, England. It has a population of approximately 1,000 residents.
The village is situated near several key locations, positioned about 3 miles north-east of Stony Stratford, 4 miles north-west of Newport Pagnell, and 7 miles north of Central Milton Keynes. It is geographically separated from the county of Northamptonshire by the River Tove.