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