Tanzania regions by population size. From most to least populated

Region	Population
Dar es Salaam	4,364,541
Mwanza	2,772,509
Mbeya	2,707,410
Kagera	2,458,023
Tabora	2,291,623
Morogoro	2,218,492
Kigoma	2,127,930
Dodoma	2,083,588
Tanga	2,045,205
Mara	1,743,830
Geita	1,739,530
Arusha	1,694,310
Kilimanjaro	1,640,087
Simiyu	1,584,157
Shinyanga	1,534,808
Manyara	1,425,131
Ruvuma	1,376,891
Singida	1,370,637
Mtwara	1,270,854
Pwani	1,098,668
Rukwa	1,004,539
Iringa	941,238
Lindi	864,652
Njombe	702,097
Zanzibar West	593,678
Katavi	564,604
Pemba North	211,732
Pemba South	195,116
Zanzibar North	187,455
Zanzibar South and Central	115,588

Tanzania regions, districts

As of 2021 Tanzania comprises 31 regions divided into 184 districts.

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.

Reformation of Tanzania districts

Around 1972: Makete district created from Njombe.

1980: Meatu district created from Maswa.

1995: Bukombe district created from Kahama. Karatu district created from Mbulu. Mkuranga district created from Kisarawe.

Around 1995: Kilolo district created from Iringa Rural.

1996: Tandahimba district created from Newala.

1996-07: Misungwi district created from Kwimba.

Around 1998: Mbarali district created from Mbeya Rural.

2000: Kishapu district created from Shinyanga Rural.

2002: Kilindi district created from Handeni.

2002-07: Mvomero district created from Morogoro Rural.

2007-07-01: Mkinga district created from Muheza.

2012-03-02: Government created 19 new districts: Buhigwe (capital Buhigwe, created from Kasulu) Busega (capital Nyashimo, created from Magu)

Butiama (capital Butiama, created from Musoma)

Chemba (capital Chemba, created from Kondoa)

Gairo (capital Gairo, created from Kilosa)

Ikungi (capital Ikungi, created from Singida)

Itilima (capital Lagangabilili, created from Bariadi)

Kakonko (capital Kakonko, created from Kibondo)

Kalambo (capital Matai, created from Sumbwanga)

Kaliua (capital Kaliua, created from Urambo)

Kyerwa (capital Rubwera, created from Karagwe)

Mbogwe (capital Mbogwe, created from Bukombe)

Mkalama (capital Nduguti, created from Iramba)

Mlele (capital Inyonga, created from Mpanda)

Momba (capital Chitete, created from Mbozi)

Nyang’hwale (capital Kharumwa, created from Geita)

Nyasa (capital Mbamba Bay, created from Mbinga)

Uvinza (capital Lugufu, created from Kigoma)

and Wanging’ombe (capital Igwachanya, created from Njombe).