Riley m
English: in some cases a transferred use of the English surname, originally a local name from a place named with the Old English elements ryge rye + lēah clearing, meadow. There is one such place in Devon and another in Lancashire. In other cases it probably represents a respelling of the Irish surname Reilly, which is from an old Irish personal name, Raghallach, of unknown origin.
First names dictionary. 2012.