| Honorific-Prefix: | His Grace |
| The Duke of Marlborough | |
| Order1: | Lord Lieutenant of Ireland |
| Term Start1: | 11 December 1876 |
| Term End1: | 21 April 1880 |
| Monarch1: | Victoria |
| Primeminister1: | Benjamin Disraeli |
| Predecessor1: | The Duke of Abercorn |
| Successor1: | The Earl Cowper |
| Order2: | Lord President of the Council |
| Term Start2: | 8 March 1867 |
| Term End2: | 9 December 1868 |
| Monarch2: | Victoria |
| Primeminister2: | Benjamin Disraeli |
| Predecessor2: | The Duke of Buckingham and Chandos |
| Successor2: | The Earl de Grey and Ripon |
| Order3: | Member of the House of Lords as Duke of Marlborough |
| Termstart3: | 1 July 1857 |
| Termend3: | 4 July 1883 |
| Predecessor3: | George Spencer-Churchill, 6th Duke of Marlborough |
| Successor3: | George Spencer-Churchill, 8th Duke of Marlborough |
| Birth Date: | 2 June 1822 |
| Birth Place: | Garboldisham Hall, Garboldisham, Norfolk, England |
| Death Place: | Berkeley Square, Mayfair, London, England |
| Nationality: | British |
| Party: | Conservative |
| Alma Mater: | Oriel College, Oxford |
| Children: |
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John Winston Spencer-Churchill, 7th Duke of Marlborough, (2 June 18224 July 1883), styled Earl of Sunderland from 1822 to 1840 and Marquess of Blandford from 1840 to 1857, was a British Conservative cabinet minister, politician, peer, and nobleman. He was the paternal grandfather of Prime Minister Sir Winston Churchill.
John Spencer-Churchill was born at Garboldisham Hall, Norfolk, the eldest son of George Spencer-Churchill, 6th Duke of Marlborough, and Lady Jane Stewart, daughter of Admiral George Stewart, 8th Earl of Galloway. He was educated at Eton College and Oriel College, Oxford.
He was commissioned as a lieutenant in the Queen's Own Oxfordshire Yeomanry in 1842 and was promoted to captain on 22 April 1847. His father and younger brother also served in the regiment.[1]
He held 23,000 acres, mostly in Oxfordshire.[2]
Spencer-Churchill was Member of Parliament for Woodstock from 1844 to 1845 and again from 1847 to 1857. He was responsible for the "Blandford Act" of 1856, enabling populous parishes to be divided for purposes of Church work. In 1857, he succeeded his father in the dukedom and entered the House of Lords.
He served under Lord Derby as Lord Steward of the Household from 1866 to 1867, and under Derby and later Benjamin Disraeli as Lord President of the Council—with a seat in the cabinet—from 1867 to 1868.He was sworn of the Privy Council in 1866, and made a Knight of the Garter in 1868. On the formation of Disraeli's second cabinet in 1874, he was offered, but declined, the Viceroyalty of Ireland. He again held office under Disraeli as Lord Lieutenant of Ireland from 1876 to 1880.
Spencer-Churchill was president of The Shipwrecked Fishermen and Mariners' Royal Benevolent Society for many years. He died suddenly of angina pectoris at 29 Berkeley Square, London, on 4 July 1883. After lying in state at Blenheim Palace, he was buried in the private chapel on 10 July.
On 12 July 1843, Spencer-Churchill married Lady Frances Anne Emily Vane (15 April 182216 April 1899), eldest daughter of the 3rd Marquess of Londonderry and Lady Frances Anne Emily Vane-Tempest. They had eleven children:
Marlborough died on 4 July 1883, aged 61, and was succeeded in the title by his eldest son, George. His wife died sixteen years later, on 16 April 1899, aged 77.
Marlborough was portrayed by Cyril Luckham in the 1974 Thames Television mini-series .