Is the name Niall an Irish name?

Yes, Niall is an Irish name. It is the Gaelic form of the name Neil, which is derived from the Old Irish name Niall. The name Niall has been in use in Ireland for centuries, and it is still a popular name today. There have been many notable people with the name Niall, including Niall of the Nine Hostages, High King of Ireland in the 5th century, and Niall Horan, a member of the band One Direction.