Naoiri (直入郡 Naoiri-gun) was a district located in Ōita, Japan.
As of 2003, the district had an estimated population of 10,956 and the density of 39.58 persons per km². The total area was 276.84 km².
Until March 31, 2005, the district had three towns. On April 1, 2005, all towns within the district merged with the old city of Taketa to form the new city of Taketa.