As of 2021, there are 31 regions (Swahili: mkoa, plural mikoa) of Tanzania which are divided into 184 districts (Swahili: wilaya). In 2016, Songwe Region was created from the western part of Mbeya Region. The districts are each administered by a district council. Cities are separately administered by their own councils, and while administratively within a region, are not considered to be located within a district. The districts are listed below, by unofficial area then region:

Ten most populated districts

(1,775,049 inhabitants) (1,368,881 inhabitants) (1,220,611 inhabitants) (807,619 inhabitants) (663,034 inhabitants) (540,310 inhabitants) (523,802 inhabitants) (502,252 inhabitants) (492,441 inhabitants) (466,737 inhabitants)

Central

Dodoma Region

Singida Region

Tabora Region

Coast

Dar es Salaam Region

Lindi Region

Morogoro Region

Mtwara Region

Pwani Region

Lake

Kagera Region

Kigoma Region

Geita Region

Mara Region

Mwanza Region

Shinyanga Region

Simiyu Region

North

Arusha Region

Kilimanjaro Region

Manyara Region

Tanga Region

South

Iringa Region

Katavi Region

Mbeya Region

Njombe Region

Rukwa Region

Ruvuma Region

Songwe Region

Zanzibar

Mjini Magharibi Region

Zanzibar North Region

Unguja South Region

Pemba North Region

Pemba South Region