John Spencer Churchill
- Category : 1897-births
- Type : MGE
- Profile : 4/6 - Opportunistic / Role Model
- Definition : Single
- Incarnation Cross : RAX Eden 3
British peer, styled the Marquess of Blandford at birth. He was the first of two sons born to Charles Spencer-Churchill, 9th Duke of Marlborough and his first wife, the former Consuelo Vanderbilt, an American railroad heiress. Prior to inheriting the dukedom in 1934 (thus becoming the 10th Duke of Marlborough) he was a lieutenant-colonel in the Life Guards. He was Mayor of Woodstock from 1937 to 1942.
He married twice; two sons and three daughters. He died in London on 11 March 1972 at age 74.