William Gerard Hamilton (January 28, 1729 - July 16, 1796), English statesman, popularly known as "Single Speech Hamilton," was born in London, the son of a Scottish bencher of Lincoln's Inn.

He was educated at Winchester and at Oriel College, Oxford. Inheriting his father's fortune he entered political life and became MP for Petersfield, Hampshire. His maiden speech, delivered on November 13, 1755, during the debate on the address, which excited Walpole's admiration, is generally supposed to have been his only effort in the House of Commons. But the nickname "Single Speech" is undoubtedly misleading, and Hamilton is known to have spoken with success on other occasions, both in the House of Commons and in the Irish parliament.

In 1756 he was appointed one of the commissioners for trade and plantations, and in 1761 he became chief secretary to Lord Halifax, the Lord Lieutenant of Ireland, as well as Irish MP for Killebegs and English MP for Pontefract. He was chancellor of the exchequer in Ireland in 1763, and subsequently filled various other administrative offices. Hamilton was thought very highly of by Dr Johnson, and it is certain that he was strongly opposed to the British taxation of America. He died in London on the 16th of July 1796, and was buried in the chancel vault of St Martins-in-the-Fields.

Two of his speeches in the Irish House of Commons, and some other miscellaneous works, were published after his death under the title Parliamentary Logick.