Where the Riley name comes from

Riley has two separate roots, one English and one Irish. The English name comes from Ryley in Lancashire, a place named from Old English ryge, "rye", and leah, "clearing" or "meadow", so it first meant a rye clearing. Several places carried the name, among them High Riley in Accrington and another in Devon. Rileys can be traced in east Lancashire and over the county boundary into the Calder Valley in Yorkshire from the 13th century. In the 1881 census, more than a third of all Rileys in the United Kingdom lived in Lancashire.

The Irish Riley is an anglicized form of O'Reilly, in Gaelic Ó Raghallaigh, meaning grandson or descendant of Raghallach. Raghallach was a first name, and the surname grew from it. Riley later passed into use as a given name for men from the 19th century and for women from the 1990s.