Niamh is an Irish mythological name meaning 'bright,' 'radiant,' or 'splendor.'
Niamh (pronounced NEEV) is Irish to its marrow — a name that sounds like the sea wind off Connacht and refuses to be mistaken for anything else. It derives from the Old Irish "níam," meaning "bright" or "radiant," and like its near-cousin Áine, it was reserved for figures whose beauty and power were supernatural in kind. The spelling, seemingly impenetrable to the uninitiated, is a perfect artifact of Old Irish orthography preserved in amber.
The name's most celebrated bearer is Niamh Chinn Óir — Niamh of the Golden Hair — daughter of Manannán mac Lir, the god of the sea, in the Fenian Cycle. She rode across the waves on a white horse to the mortal world, chose the hero Oisín as her lover, and carried him to Tír na nÓg, the Land of Eternal Youth, where they lived for what felt like three years but was in fact three hundred. When Oisín returned to Ireland and touched mortal ground, he aged instantly into an ancient man.
It is one of the most hauntingly beautiful love stories in world mythology — and it belongs to Niamh. For most of the twentieth century Niamh was confined to Ireland, where it has been a perennial favorite, consistently appearing in the top twenty girls' names. The wider English-speaking world has come to it more recently, partly through Irish immigration and partly through a growing appetite for names with genuine mythological depth. Its pronunciation remains a gentle test — those who know it know something — and the name carries that quiet confidence of belonging to a tradition far older than fashion.