West Halmahera Regency (Indonesian: Kabupaten Halmahera Barat) is a regency (on Halmahera Island) in North Maluku Province of Indonesia. The regency was created on 25 February 2003 from the western districts of the former North Maluku Regency, and is now bounded by North Halmahera Regency to the north and east, while to the south it borders both East Halmahera Regency and that portion of the city of Tidore on the mainland of Halmahera. It covers an area of 2,239.11 km, and it had a population of 100,424 people at the 2010 Census and 132,349 at the 2020 Census; the official estimate as at mid 2023 was 137,543 (comprising 70,281 males and 67,262 females). The capital lies at Jailolo (town).

At the time of the 2020 Census the regency was divided into eight districts (kecamatan), but a ninth district - Loloda Tengah - has subsequently been created from the northern part of Loloda District. The districts are tabulated below with their areas and their 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 administrative centres, the number of administrative villages (all classed as rural desa) in each district, and their postal codes.

Kode Wilayah	Name of District (kecamatan)	English name	Area in km	Pop'n Census 2010	Pop'n Census 2020	Pop'n Estimate mid 2023	Admin centre	No. of villages	Post codes
82.01.05	Jailolo Selatan	South Jailolo	221.01	14,144	24,409	24,680	Domato	22	97751
82.01.01	Jailolo	(North) Jailolo	305.60	27,541	34,757	36,854	Acango	34	97752
82.01.04	Sahu	(West) Sahu	125.87	9,223	11,842	12,352	Susupu	19	97753
82.01.09	Sahu Timur	East Sahu	266.29	8,015	11,066	11,331	Akelamo	18	97758
82.01.08	Ibu Selatan	South Ibu	375.38	10,335	15,004	15,673	Talaga	16	97756
82.01.03	Ibu	(Central) Ibu	114.62	9,351	12,280	12,920	Tongute Sungi	17	97754
82.01.07	Tabaru	North Ibu	207.97	7,773	9,335	9,898	Duono	16	97757
82.01.02	Loloda	(South) Loloda	359.02	10,626	13,656	9,191	Kedi	27	97755
82.01.10	Loloda Tengah	Central Loloda	177.28			4,644	Barataku		97755
	Totals		2,239.11	100,424	132,349	137,543	Jailolo	169

Notes: (a) including 37 offshore islands. (b) including 80 offshore islands in Loloda and Loloda Tengah Districts together. The largest island is Nusa Kahatola, west of Kedi village. (c) included in the figure for Loloda District, of which it was formerly a part.