Nath Í
Nath Í, an early Irish personal name for males, may refer to:

Nath Í mac Fiachrach, 5th-century legendary king of Connacht
Nath Í of Cúl Fothirbe, saint of the Dál Messin Corb of Leinster (fl. 6th century)
Nath Í of Achonry, saint in present-day Co. Sligo, Connacht (fl. 6th century)