John Spencer-Churchill, 11th Duke of Marlborough, English businessman (d. 2014)
John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough, (13 April 1926 – 16 October 2014) was a British peer. He was the elder son of the 10th Duke of Marlborough and his wife, the Hon. Alexandra Mary Hilda Cadogan. He was known as "Sunny" after his courtesy title of Earl of Sunderland.

His principal seat was Blenheim Palace, Woodstock, Oxfordshire. He was ranked 224th in the Sunday Times Rich List 2004, with an estimated wealth of £185 million. His death was announced on 16 October 2014 by Blenheim Palace.