This unusual surname is of geographic origin, i.e. its bearers took the surname from a place, likely Rudetorp/Rudthorp, a lost settlement in the East Riding of Yorkshire. This origin would explain the various unusual renderings. Rudetorp, now part of Thrope le Street was a manor recorded in the Domesday book, held by Alwin and had six bovates of land for geld. Half of the land was in plough. The name is Scandinavian, from the Norse 'rud' or 'ruth', a clearing, and 'torp', village - village in the clearing. Alternatively it may have origins from several places called Redthorpe in Lancashire, Yorkshire, Northumberland and Surrey. Though the surname is highly concentrated near London, it appears this branch moved there from Cheshire in the 16th century. The surname was also concentrated on the border with North Wales. Thus, the surname likely arises from a place in the north. The surname has several peculiar endings, such as -rup, -robe, -rope and -rip. These endings are shared with only one other surname, Hartrup, and evidenced by a will of Harttropp, alias Herthorpe.

This surname exists in Scandinavia as Rudtorp.

• 1556. Robert Rudroppe, sup. for B.A., 25 June 1556: Oxford University.
• 1587. George Rethrop, fi Will, baptised, Ormskirk, Lancashire: Parish registers
• 1574. William Redropp, will, Meifod, Montgomeryshire
• 1578. Joane Rudrope, will, Llanymynech, Shropshire
• 1593. John Redrop: Surrey Subsidy Roll
• 1605. Richard Redrope, slain at Oswestry, Shropshire: Parish Registers
• 1609. Joane Retherup, witnessed will, Surrey.
• 1623. Anne Redrop m. Dauid Jenings, Oswestry: Parish Registers
• 1679. Richard Reddrop, snr., gent. of Melverley: marriage settlement, Shropshire Archives
• 1719. John Rederup m. Mary Perkins, St. James', Westminster,: Parish Registers
• 1830. Mary Redrobe, buried, Llanfechain, Montgomeryshire: Parish Registers