From Irish 'Raghallach' meaning 'courageous,' or Old English 'ryge leah' (rye clearing).
Riley began as a surname with several likely roots in the British Isles. In one line, it comes from Old English elements meaning "rye clearing" or "wood clearing"; in another, it is linked to an Irish surname derived from the Gaelic O'Raghailligh. Like many surnames that became given names, Riley carries a faint echo of landscape and lineage at once: a place-name turned family-name turned personal name.
That layered history helps explain why it feels both grounded and modern. For much of its early life as a given name, Riley was used more often for boys in English-speaking countries, especially in the United States. Over the late twentieth and early twenty-first centuries, it became one of the clearest examples of a name crossing gender lines and settling comfortably into unisex use, though in recent years it has often skewed feminine in popular perception.
Its bright, upbeat sound helped that shift along; Riley feels friendly, athletic, and approachable, with a touch of Irish charm whether or not the bearer has Irish ancestry. Culturally, Riley has been helped by its easy presence in television, sports, and everyday American naming styles that favor surnames as first names. It carries none of the stiffness that some inherited surnames do. Instead, it has evolved into a name associated with energy, warmth, and independence, one that sounds equally at home on a child, a novelist's heroine, or a contemporary professional.