West Seram Regency is a regency of Maluku, Indonesia. It is mainly located on Seram, but includes various islands lying to the west of Seram - the largest being Manipa, Kelang and Boano, as well as the smaller islets of Babi, Pua, Masowoi, and Marsegu. It covers a land area of 6,948.40 km, and had a population of 164,654 at the 2010 Census and 212,393 at the 2020 Census; the official estimate as at mid 2023 was 214,979. The principal town lies at Piru, a port at the northern coast of Latira Bay (Teluk Latira) which is a northwards extension of Piru Bay (Teluk Piru) and almost separates the Huamual Peninsula from the rest of Seram Island. The western sector of the Regency (the Huamual Peninsula and the islands off the west coast) occupies just under 25% of the land area, but held over 42% of the Regency's population at the 2020 Census.

At the time of the 2010 Census the regency was divided into four districts (kecamatan). Subsequent to 2010, seven additional districts have been created by the division of the original four districts, so that the regency is now divided into eleven districts. These are tabulated below with their areas and populations at the 2010 Census and 2020 Census, together with the official estimates as at mid 2023. The table also includes the locations of the district headquarters, as well as the number of administrative villages (all classed as rural desa) in each district, and its postal 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	Post code
81.06.04	Huamual Belakang	409.65	25,629	33,132	35,229	Waesala	7	97567
81.06.09	Kepulauan Manipa (Manipa Islands)	159.71	5,810	7,165	7,793	Masawoi	7	97569
81.06.08	Huamual	1,162.99	34,919	49,097	46,967	Luhu	5	97560
	Totals of Western sector	1,732.35	66,358	89,394	89,989		19
81.06.02	Seram Barat (West Seram)	503.33	27,311	35,045	35,598	Piru	7	97562
81.06.01	Kairatu	329.65	23,240	27,040	26,717	Kairatu	7	97566
81.06.07	Kairatu Barat (West Kairatu)	132.25	13,146	14,478	14,160	Kamal	6	97568
81.06.06	Inamosol	504.61	5,311	6,422	6,777	Honitetu	5	97565
81.06.05	Amalatu	665.35	10,979	12,537	13,131	Latu	7	97563
81.06.11	Elpaputih	1,165.74	1,453	5,233	5,105	Elpaputih	7	97564
81.06.03	Taniwel	1,181.32	12,133	15,448	16,047	Taniwel	19	97559
81.06.10	Taniwel Timur (East Taniwel)	733.80	5,375	6,796	7,455	Uwen Pantai	15	97561
	Totals of Eastern sector	5,216.05	98,948	122,999	124,990		73
	Totals	6,948.40	164,654	212,393	214,979		92

Notes: (a) Huamual Belakang District includes Boano and Kelang Islands, as well as Babi (a small island situated between Kelang Island and Seram), Pua (a small island off Boano) and 26 other small islands, as well as part of the 'mainland' of Seram (the 2 desa of Waesala and Allang Asaude).
(b) Manipa Islands District consists of the main island of Manipa together with adjacent small islands; it was formerly part of Huamual Belakang District.
(c) formerly part of Seram Barat District; in the north it is now bordered by Huamual Belakang and Seram Barat Districts, in the south it is bordered by the Banda Sea, in the east it is bordered by Seram Barat District, and in the west it is bordered by the Manipa Passage. The district comprises 5 towns and villages (all desa) - Lohu (with 26,184 inhabitants in mid 2022), Lokki (12,568), Iha (6,210), Ariate (1,182) and Kulur (918).
(d) the 7 desa are Piru (a town with 16,368 inhabitants in mid 2022), Kaibobo, Eti, Lumoli, Morekau, Neniari and Kawa.
(e) formerly part of Kairatu District. (f) formerly part of Taniwel District.