Riley is a surname of English origin, as well as an Anglicized version of an Irish surname.
The name has the meaning "rye clearing", or is from one of several placenames, including High Riley in Accrington, Lancashire, and in Devon.[1][2] In the United Kingdom Census 1881, more than a third of Rileys were in Lancashire; it was most prevalent in the east of the county and over the boundary into the Calder Valley in Yorkshire, and the name could be found in these areas from the 13th century.[3] The name is also an Anglicized version of the Irish surname O'Reilly.[1] This is derived from the first name Raghallach; the Gaelic version of the surname, Ó Raghallaigh, is Irish for 'grandson (or descendant) of Raghallach'.