South Aceh Regency () is a regency in the Aceh province of Indonesia. It is located on the west coast of the island of Sumatra. The regency covers an area of 4,173.82 square kilometres and had a population of 202,251 at the 2010 Census, 224,588 at the 2015 Census and 232,414 at the 2020 Census; the official estimate as at mid 2022 was 237,376. Its population density at the 2010 census is inhabitants/km2, while the population density at the 2015 census is inhabitants/km2, inhabitants/km2 at the 2020 census and the population density in mid 2022 is inhabitants/km2. The seat of the regency government is at Tapaktuan. Some of the people of the regency are Minangkabau-descended Aneuk Jamee.
Administrative districts
At the time of the 2010 Census, the regency was divided administratively into sixteen districts (kecamatan). Subsequent to 2010, two additional districts (Trumon Tengah and Kota Bahagia) were created by being carved out of existing districts. The districts are listed below with their areas and populations at the 2010 Census and the 2020 Census, together with the official estimates for mid 2022. The table also includes the locations of the district administrative centres, the number of villages (gampong) in each district, and its postal codes.
Note: (a) including small offshore islands. (b) The 2010 population of Trumon Tengah District is included in the 2010 figure for Trumon Timur District, from which it was split. (c) The Trumon area which forms the southern 28% of the Regency is adjacent to the city of Subulussalam to the east. (d) The 2010 population of Kota Bahagia District is included in the 2010 figure for Bakongan District, from which it was split.