Mongun-Tayginsky District (; , Möñgün-Tayga kojuun) is an administrative and municipal district (raion, or kozhuun), one of the seventeen in the Tuva Republic, Russia. It is located in the southwest of the republic. Its administrative center is the rural locality (a selo) of Mugur-Aksy. Population: 5,938 (2002 Census); The population of Mugur-Aksy accounts for 73.4% of the district's total population.