Momsky District (; ) is an administrative and municipal district (raion, or ulus), one of the thirty-four in the Sakha Republic, Russia. It is located in the northeast of the republic. The area of the district is . Its administrative center is the rural locality (a selo) of Khonuu. Population: 4,699 (2002 Census); The population of Khonuu accounts for 55.6% of the district's total population.