Aceh Singkil Regency (Indonesian: Kabupaten Aceh Singkil) is a regency in the Aceh province of Indonesia. It is situated largely on the island of Sumatra, but also includes the offshore Banyak Islands, the largest of which is Tuangku (Great Banyak), with the principal town of Alaban. The regency was created on 20 April 1999 from the former southern districts of South Aceh Regency. Until 2007 it included the large town of Subulussalam, but on 2 January of that year that town was split off to become an autonomous city. The seat of the Aceh Singkil Regency government is at the port of Singkil on the Sumatra coast. The Regency now covers an area of 1,857.88 km, and had a population of 102,509 at the 2010 Census, rising to 114,326 at the 2015 Census and to 126,514 at the 2020 Census; the official estimate as at mid 2023 was 135,435.

At the time of the 2010 Census, the regency was divided administratively into ten districts (kecamatan). Subsequent to 2010, the Banjak Islands District was divided into two, with a new Western Banjak Islands District (Kecamatan Pulau Banjak Barat) being carved out of the existing district, the residual district now essentially restricted to Pulau Balai. The districts are listed below with their areas and their populations at the 2010 Census and the 2020 Census, together with the official estimates as at mid 2023. The table also includes the locations of the district administrative centres, the number of villages (all classed as kampong) and the number of offshore islands in each district, and its post code.

Kode Wilayah	Name of District (kecamatan)	Area in km	Pop'n Census 2010	Pop'n Census 2020	Pop'n Estimate mid 2023	Admin centre	No. of villages	No. of offshore islands	Post code
11.10.01	Pulau Banyak (Banyak Islands)	15.02	6,570	4,562	4,711	Pulau Balai	3	1	24791
11.10.16	Pulau Banyak Barat (Western Banyak Islands)	278.63		3,078	3,180	Haloban	4	74	24790
11.10.04	Singkil	135.94	16,292	19,740	20,797	Pulo Sarok	16	1	24785
11.10.10	Singkil Utara (North Singkil)	142.83	8,918	10,533	11,092	Ketapang Indah	7	1	24791
11.10.14	Kuala Baru	45.83	2,173	2,555	2,682	Kuala Baru	4	-	24789
11.10.02	Simpang Kanan	289.96	12,716	15,748	17,423	Lipat Kajang	25	-	24794
11.10.06	Gunung Meriah	224.30	30,630	39,557	42,452	Rimo	25	-	24793
11.10.11	Danau Paris	206.04	6,622	7,883	8,655	Biskang	6	-	24784
11.10.12	Suro (Suro Makmur)	127.60	7,559	8,989	9,556	Bulusema	11	-	24787
11.10.13	Singkohor	159.63	5,309	7,265	7,844	Singkohor	6	-	24788
11.10.09	Kota Baharu	232.69	5,720	6,606	7,043	Danau Bungara	9	1	24792
	Totals	1,857.88	102,509	126,514	135,435		116	78

Note: (a) The 2010 population of Pulau Banyak Barat District is included in the 2010 figure for Pulau Banyak District, from which it was split out.

Banyak means "many" because there are 99 islands, of which only a few are inhabited. Yachts from Nias Island or directly from abroad carries foreign tourists to Big Palambak Island or Small Palambak Island for fresh water and snorkelling. Tailena Island, Rago-rago Island, Panjang (Long) Island and Matahari (Sun) Island are also suitable for scuba diving, while in Tuwanku (My Master) Island a conservation area for penyu hijau (green sea turtle) and penyu belimbing (leatherback sea turtle) is established.

• List of regencies and cities of Indonesia

• Aceh Singkil Tourism