Ust-Yansky District (Russian: Усть-Я́нский улу́с; Yakut: Усуйаана улууһа, Usuyaana uluuha, Yakut pronunciation: [usujaːna uluːha]) is an administrative[1] and municipal[6] district (raion, or ulus), one of the thirty-four in the Sakha Republic, Russia.

[4] The main rivers in the district include the Yana, the Omoloy with the Ulakhan-Kyuegyulyur, the Sellyakh, as well as the Chondon with its tributary the Nuchcha.

In the 2021 census, the indigenous Yakuts again formed a plurality (around a half) of the inhabitants, with the total population now just 6,810.

In that year, the ethnic composition of the district was:[15] The main industries are gold mining, reindeer herding, fishing, and fur trade.

There are deposits of gold, tin, tungsten, mercury, lead, zinc, and brown coal.