Manyoni is one of the 4 districts in the Singida Region of Tanzania. The district capital is Manyoni. The district is bordered to the North by the Singida Rural and Singida Urban Districts, to the East by the Dodoma Region, to the South by the Iringa Region, to the Southwest by the Mbeya Region and to the West by the Tabora Region.
According to the 2002 Tanzania National Census, the population of the Manyoni District was 205,423.
The District Commissioner of the Manyoni District is Ernest D. Masima.