Reilly

Reilly is a unisex given name of modern English usage, derived from an Irish surname. It is an Anglicized form of Ó Raghailligh, meaning "descendant of Raghallach," a personal name of uncertain etymology. The name has gained popularity as a first name in the late 20th and early 21st centuries, particularly in the United States.

Etymology

The surname Reilly, along with its variants such as Riley, Rally, and O'Reilly, originates from the Gaelic Ó Raghallaigh. The root Raghallach is a given name whose meaning is debated; it may derive from elements meaning "valiant" or "powerful," but no definitive translation exists. The name is historically associated with County Cavan in Ireland, where the O'Reilly clan was a prominent Gaelic dynasty. According to Irish annals, the O'Reillys (Uí Raghallaigh) were chiefs of East Bréifne from the 13th to the 17th centuries.

Cultural Significance

The Reilly surname is widespread in Ireland and the Irish diaspora, ranking 845th in frequency in the United States as of the 2010 census, where it is predominantly held by individuals of White ethnicity (95.3%). As a first name, Reilly is often chosen for its phonetic appeal and cultural heritage, appealing to parents seeking unisex options. The phrase "life of Reilly" (meaning a life of ease and luxury) may have influenced its popularity, though the phrase's origin is uncertain.

• Meaning: Descendant of Raghallach (meaning unknown)
• Origin: Irish (Gaelic)
• Type: Unisex first name (transferred from surname)
• Usage: English-speaking world (especially U.S., Ireland)