Nganjuk Regency is a regency (kabupaten) of East Java Province, Indonesia. It borders Bojonegoro Regency in the north, Jombang Regency in the east, Kediri Regency in the south and Madiun Regency in the west. It covers an area of 1,224.33 sq. km, and had a population of 1,017,030 at the 2010 Census and 1,103,902 at the 2020 Census; the official estimate as of mid-2023 was 1,144,508 (comprising 575,671 males and 568,837 females). The administrative centre of the regency is the town of Nganjuk. The current regent is Dr. Drs. H. Marhaen Djumadi, S.E., S.H., M.M., M.B.A.

The Regency is divided into twenty districts (kecamatan), tabulated below with their areas and their population totals from the 2010 Census and the 2020 Census, together with the official estimates as of mid-2023. The table also includes the location of the district headquarters and the number of administrative villages in each district (totaling 264 rural desa and 20 urban kelurahan), and its postcodes.

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 codes
35.18.01	Sawahan	115.89	36,015	38,670	39,890	Sawahan	9	64475
35.18.02	Ngetos	60.21	34,112	37,574	39,410	Ngetos	9	64474
35.18.03	Berbek	48.30	53,732	58,955	60,550	Berbek	19	64473
35.18.04	Loceret	68.70	68,909	75,315	78,140	Loceret	22	64471
35.18.05	Pace	48.46	58,983	65,706	68,730	Pace	18	64472
35.18.11	Tanjunganom	70.84	108,631	117,014	121,110	Tanjunganom	16	64482
35.18.06	Prambon	41.16	68,524	72,788	75,050	Prambon	14	64484
35.18.07	Ngronggot	52.99	75,084	83,038	86,560	Ngronggot	13	64395
35.18.08	Kertosono	22.68	52,405	56,182	57,060	Kertosono	14	64311 - 64315
35.18.09	Patianrowo	35.59	40,890	44,370	46,040	Patianrowo	11	64391
35.18.10	Baron	36.80	48,069	54,068	56,260	Baron	11	64394
35.18.17	Gondang	95.94	50,027	55,026	57,490	Gondang	17	64451
35.18.12	Sukomoro	35.39	41,566	45,988	48,420	Sukomoro	12	64481
35.18.13	Nganjuk	22.59	65,917	69,011	70,630	Nganjuk	15	64411 - 64419
35.18.14	Bagor	51.15	56,753	61,181	63,710	Bagor	21	64461
35.18.15	Wilangan	50.64	26,910	30,222	31,510	Wilangan	6	64462
35.18.16	Rejoso	151.66	66,167	71,347	73,910	Rejoso	24	64453
35.18.18	Ngluyu	86.15	13,688	14,160	14,480	Ngluyu	6	64452
35.18.19	Lengkong	87.17	31,212	32,998	34,370	Lengkong	16	64393
35.18.20	Jatikalen	42.04	19,436	20,289	21,200	Jatikalen	11	64392
	Totals	1,224.33	1,017,030	1,103,902	1,144,508	Nganjuk	284

Notes: (a) except the desa of Gondang, which has a postcode of 64451. (b) including 2 kelurahan (Tanjunganom and Warujayeng).
(c) including one kelurahan (Banaran). (d) including 2 kelurahan (Kapas and Sukomoro).
(e) comprising 13 kelurahan (Begadung, Bogo, Cangkringan, Ganungkidul, Jatirejo, Kartoharjo, Kauman, Kramat, Mangundikaran, Payaman, Ploso, Ringinanom and Werungotok) and 2 desa.
(f) including 2 kelurahan (Guyangan and Kedondong).

Nganjuk has a tropical savanna climate (Aw) with moderate to little rainfall from May to October and heavy rainfall from November to April. The following climate data is for the city of Nganjuk.

• Shendy Puspa Irawati, badminton player
• Harmoko, Former chairman of People's Representative Council in the Era of President Soeharto
• Erni Suyanti Musabine, veterinarian involved in the conservation of Sumatran tigers