George Nugent-Temple-Grenville, 1st Marquess of Buckingham (17 June 1753 – 11 February 1813) was a British statesman; he was the second son of George Grenville and a brother of the 1st Baron Grenville.
Educated at Eton College and Christ Church, Oxford, he was appointed a Teller of the Exchequer in 1764, and ten years later was returned to Parliament as one of the Members for Buckinghamshire. In the House of Commons he was a sharp critic of the American policy of Lord North. In September 1779 he succeeded his uncle as Earl Temple; in 1782 was appointed Lord Lieutenant of Buckinghamshire; and in July of the same year became a member of the Privy Council and Lord Lieutenant of Ireland in the Ministry of Lord Shelburne. On his advice the Renunciation Act 1783 was passed, which supplemented the legislative independence granted to Ireland in 1782. By Royal Warrant he created the Order of St Patrick in February 1783, with himself as the first Grand Master. Lord Temple left Ireland in 1783, and again turned his attention to English politics. He enjoyed the confidence of King George III, and having opposed Fox's East India Bill, he was authorized by the King to say that "whoever voted for the India Bill was not only not his friend, but would be considered by him as an enemy", a message which ensured the defeat of the Bill. He was appointed a Secretary of State when the younger Pitt formed his Ministry in December 1783, but resigned two days later. In December 1784 he was created Marquess of Buckingham.
In November 1787 he was appointed Lord Lieutenant of Ireland under Pitt, but his second tenure of this office was hardly as successful as the first. He was denounced by Grattan for extravagance; was censured by the Irish Houses of Parliament for refusing to transmit to England an address calling upon the Prince of Wales to assume the regency; and he could only maintain his position by resorting to bribery on a large scale. Having become very unpopular he resigned his office in September 1789 and subsequently took very little part in politics, although he spoke in favour of the union with Ireland. He died at his residence, Stowe in Buckinghamshire, on 11 February 1813, and was buried at Wotton.