Mazanovsky District () is an administrative and municipal district (raion), one of the twenty in Amur Oblast, Russia. The area of the district is . Its administrative center is the rural locality (a selo) of Novokiyevsky Uval. Population: 16,028 (2002 Census); The population of Novokiyevsky Uval accounts for 29.2% of the district's total population.
River Selemdzha and its tributaries Ulma and Orlovka flow across the district.