James George Hamilton, 6th Duke of Hamilton and 3rd Duke of Brandon, KT (10 July 1724 – 17 January 1758) was a Scottish peer.
Hamilton was the son of the 5th Duke of Hamilton and was styled as Marquess of Clydesdale from his birth until his father's death. He was educated at Winchester College from 1734 to 1740 and graduated from St Mary Hall, Oxford on 14 April 1743.
On 14 February (St. Valentine's Day) 1752, Hamilton met the society beauty Elizabeth Gunning at Bedford House in London. According to Robert Walpole, the duke wished to marry her that night and he called for a local parson to perform the ceremony. However, without a licence, calling of banns and a ring, the parson refused and they were eventually married that night in Mayfair Chapel (which did not require a licence) in a clandestine marriage, with a ring from a bed curtain. The couple had three children:
On 2 March 1743, he succeeded to his father's title of Duke of Hamilton.
He died on 17 January 1758, aged 33, at Great Tew, Oxfordshire from a cold caught whilst out hunting. He was buried in February 1758 at the family mausoleum at Hamilton, South Lanarkshire.
The Duke of Hamilton was a member of the local Masonic Lodge (Hamilton Kilwinning No. 7) and in fact presided as Master of that lodge for three consecutive years from 1753 to 1755.