The surname Mainwaring (/ˈmænərɪŋ/ or /ˌmeɪnˈwɛərɪŋ/) 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:
Chris Mainwaring (1965–2007), Australian rules footballer and TV presenter
Daniel Mainwaring (1902–1977), American novelist and screenwriter
George Boulton Mainwaring (c. 1773-unknown), British politician
Henry Mainwaring (c. 1586-1653), pirate, lawyer, author and diplomat
Marion Mainwaring (b. 1922), American novelist
Matty Mainwaring (b. 1990), English footballer
Ranulph Mainwaring, Justice of Chester in the reign of Richard I (1189-1199)
Sam Mainwaring (1841–1907), Welsh socialist and syndicalist trade union activist
Sam Mainwaring, Jr., labor activist in Britain, South Africa and the United States; nephew of Sam Mainwaring
William Mainwaring (1884–1971), British miner and politician
William Mainwaring (English politician) (in office 1786-1802), English politician, father of George Boulton Mainwaring
