George Montagu, 4th Duke of Manchester PC (6 April 1737 – 2 September 1788) was a British politician and diplomat.
He was the son of Robert Montagu, 3rd Duke of Manchester.
Manchester was Member of Parliament for Huntingdonshire from 1761 to 1762, when he inherited his father's title.
He was a supporter of Lord Rockingham, and an active opponent in the House of Lords of Lord North's American policy.
In the Rockingham ministry of 1782 Manchester became Lord Chamberlain, and in the same year he was appointed a Privy Councillor.
Manchester signed the Peace of Paris (1783) for Great Britain to end the American Revolutionary War.
Manchester married Elizabeth Dashwood, daughter of Sir James Dashwood, 2nd Baronet, on 22 October 1762.
They had several children, including:
George Montagu, Viscount Mandeville (1763–1772)
Caroline Maria Montagu (1770–1847), married James Graham, 3rd Duke of Montrose, and had issue.
William Montagu, 5th Duke of Manchester (1771–1843)
Lord Frederick Montagu (1774–1827)