John Spencer-Churchill, 11th Duke of Marlborough

His Grace The Duke of Marlborough JP DL
Portrait by Allan Warren, 1984
Member of the House of Lords as Duke of Marlborough
In office 10 March 1972 – 11 November 1999
Preceded by	The 10th Duke of Marlborough
Succeeded by	House of Lords Act 1999
Personal details
Born	John George Vanderbilt Henry Spencer-Churchill (1926-04-13)13 April 1926 Blenheim Palace, Oxfordshire, England
Died	16 October 2014(2014-10-16) (aged 88) Woodstock, Oxfordshire, England
Spouses	Susan Mary Hornby ​ ​ (m. 1951; div. 1961)​ Tina Onassis ​ ​ (m. 1961; div. 1971)​ Countess Rosita Douglas ​ ​ (m. 1972; div. 2008)​ Lily Sahni ​ (m. 2008)​
Children	John Spencer-Churchill, Earl of Sunderland James Spencer-Churchill, 12th Duke of Marlborough Lady Henrietta Spencer-Churchill Lord Richard Spencer-Churchill Lord Edward Spencer-Churchill Lady Alexandra Spencer-Churchill
Parents	John Spencer-Churchill, 10th Duke of Marlborough Hon. Alexandra Cadogan
Residence	Blenheim Palace

John George Vanderbilt Henry Spencer-Churchill, 11th Duke of Marlborough, JP, DL (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.