The surname Mainwaring ( or ) is an Anglo-Norman territorial surname deriving from "Mesnil Warin" (or "Mesnilwarin", "Mesnilvarin", "Mesnil Varin"), from the village of Le Mesnil Varin (= "the manor of Warin"), now Saint-Paër, Normandy.

Notable people with the surname include:

People

Billy Mainwaring (1941–2019), Welsh international second row rugby union player who played for Aberavon RFC Chris Mainwaring (1965–2007), Australian rules footballer and TV presenter Daniel Mainwaring (1902–1977), American novelist and screenwriter George Mainwaring (1642–1695), English politician George Boulton Mainwaring (c. 1773–unknown), British politician George Byers Mainwaring (1824–1894), British Indian army officer and linguist Henry Mainwaring (1587–1653), English pirate, lawyer, author and diplomat John Mainwaring (1724–1807), English theologian and first biographer of the composer Georg Friedrich Händel Marion Mainwaring (1922–2015), American novelist Matty Mainwaring (b. 1990), English footballer and boxer Sam Mainwaring (1841–1907), Welsh socialist and syndicalist trade union activist William Mainwaring (1884–1971), British miner and politician William Mainwaring (English politician) (1735–1821), English politician, father of George Boulton Mainwaring

In fiction Captain George Mainwaring, commander of the Home Guard platoon in the BBC sitcom Dad's Army Elizabeth Mainwaring, Captain Mainwaring's wife Barry Mainwaring, Captain Mainwaring's long-lost brother Veronica Mainwaring, protagonist in Demon Lover, 1929 novel by Dion Fortune

See also Mainwaring baronets Mainwaring (HBC vessel), operated by the HBC from 1807 to 1820; see Hudson's Bay Company vessels Mannering, a surname Manwaring, a surname