The reduced Mamuju Regency covers an area of 4,979.89 km2 and had a population of 278,764 at the 2020 Census;[3] the official estimate as at mid 2023 was 292,395 (comprising 149,395 males and 142,844 females).

[1] The regency is divided into eleven districts (kecamatan), tabulated below with their areas and their populations at the 2010 Census[2] and 2020 Census,[3] together with the official estimates for mid 2023.

[1] The table also includes the locations of the district administrative centres, the number of administrative villages in each district (totalling 88 rural desa and 14 urban kelurahan), and its post code.

(b) including offshore island of Pulau Karampuang to the north of the town.

(e) the Balabalakang Islands are a small group lying between West Sulawesi and East Kalimantan, and closer to the latter.