The Nagnatae or Magnatae (Μαγναται) were a people of ancient Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

, recorded in Ptolemy

Ptolemy

Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

's 2nd century Geography as living in northern Connacht

Connacht

Connacht , formerly anglicised as Connaught, is one of the Provinces of Ireland situated in the west of Ireland. In Ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for...

. Ptolemy also records a town, Nagnata (Ναγνατα) or Magnata (Μαγνατα), in their territory, between the mouths of the rivers Ravius (Ῥαουιος), thought to be the Roe, and Libnius (Λιβνιος), thought to the Erne

River Erne

The River Erne , in the northwest of Ireland, rises in Beaghy Lough, two miles south of Stradone in County Cavan and flows 64 miles through Lough Gowna, Lough Oughter and Upper and Lower Lough Erne, County Fermanagh, to the sea at Ballyshannon, County Donegal...

. O'Rahilly

T. F. O'Rahilly

Thomas Francis O'Rahilly was an Irish scholar of the Celtic languages, particularly in the fields of Historical linguistics and Irish dialects. He was a member of the Royal Irish Academy.-Biography:He was born in Listowel, County Kerry, Ireland...

 suggests a connection between the Nagnatae and the Fir Ól nÉcmacht, a people of early Connacht, assuming a degree of corruption in the transmission of both names.