George I (George Louis; German: Georg Ludwig; 28 May 1660 – 11 June 1727) was King of Great Britain and Ireland from 1 August 1714 and ruler of the Duchy and Electorate of Brunswick-Lüneburg (Hanover) within the Holy Roman Empire from 23 January 1698 until his death in 1727. He was the first British monarch of the House of Hanover.

Born in Hanover to Ernest Augustus and Sophia of Hanover, George inherited the titles and lands of the Duchy of Brunswick-Lüneburg from his father and uncles. A succession of European wars expanded his German domains during his lifetime; he was ratified as prince-elector of Hanover in 1708. After the deaths in 1714 of his mother, and his second cousin Anne, Queen of Great Britain, George ascended the British throne as Anne's closest living Protestant relative under the Act of Settlement 1701. Jacobites attempted, but failed, to depose George and replace him with James Francis Edward Stuart, Anne's Catholic half-brother.

During George's reign, the powers of the monarchy diminished and Britain began a transition to the modern system of cabinet government led by a prime minister. Towards the end of his reign, actual political power was held by Robert Walpole, now recognised as Britain's first de facto prime minister. George died of a stroke on a trip to his native Hanover, where he was buried. He is the most recent British monarch to be buried outside the United Kingdom.