The Mainwaring baronetcy of Over-Peover was created for the second time, on 26 May 1804 in the Baronetage of the United Kingdom, for Henry Mainwaring ne Wetenhall, son of Thomas Mainwaring ne Wetenhall.
The first creation of the baronetcy became extinct in 1797, on the death of Sir Henry Mainwaring, 4th Baronet. His mother had remarried and her son by the second marriage, Thomas Wetenhall (1736–1798), inherited the Mainwaring Cheshire estate on the death of his half-brother; he changed his surname to Mainwaring. His son Henry Mainwaring became the first baronet of the second creation.[1]