Onga (遠賀郡 Onga-gun?) is a district located in Fukuoka Prefecture, Japan.
According to 2005 Japanese Census data, the district has a population of 97,537 and a density of 1,045.73 persons per km². The total area is 93.10 km².
Coordinates: 33°51′50″N 130°38′10″E / 33.864°N 130.636°E