Oneil

Irish

"from the chief's line"

Oneil Origin and Meaning

The name Oneil is a boy's name.

Oneil is a masculine name derived from the Gaelic surname Ó Néill, meaning "descendant of Niall." The original Niall was a legendary 4th-century Irish high king, Niall of the Nine Hostages, making this a name with ancient royal connections. The O'Neill clan became one of Ireland's most powerful dynasties, ruling parts of Ulster for centuries. As a first name, Oneil gained modest popularity in the 20th century, particularly in Irish-American communities and Caribbean nations with Irish colonial influence. The name offers a strong connection to Irish heritage while being more distinctive than common Irish names like Patrick or Sean. The single-word spelling (versus O'Neil) simplifies the name while maintaining its cultural roots.