Riley is either an Irish surname, the anglicized Ó Raghailligh of uncertain meaning, or an English place name from ryge leah, "rye clearing" or "rye meadow". It was a boys' name for most of the 20th century, but in the United States it has been given mainly to girls since the early 2000s. Riley ranked number 131 among American girls in 2000, entered the top 100 in 2002, peaked at number 22 in 2016 and ranks number 48 in 2025.