Koyu (児湯郡, Koyu-gun) is a district in Miyazaki Prefecture, Japan.
As of October 1, 2019, the district has an estimated population of 68,269 and the density of 95.5 persons per km2. The total area is 715.03 km2.
Towns and villages
edit32°14′56″N 131°28′59″E / 32.249°N 131.483°E