Fir Ol nEchmacht was the name of a group or race of people living in pre-historic Ireland. The name may be translated as "men (Fir) of the race/people (Ol, possibly Dal?) of Echmacht" (Echmacht being the given name of the people, perhaps from ech, "horse," and macht, "death/wonderful/across the sea").^[1] Some scholars believe they are connected to, or the same as, the Nagnatae tribe, mentioned in Ptolemy's 2nd century AD work Geography.^[2]

Virtually all of Ireland west of the Shannon was once named after them and was called Cóiced Ol nEchmacht until the early historic era (c. 5th-7th centuries).

It was only with the rise of the Connachta dynasty that the term Fir Ol nEchmacht was dropped and the province was renamed Connacht.