Jombang Regency (Indonesian: Kabupaten Jombang; Javanese: ꦏꦧꦸꦥꦠꦺꦤ꧀ꦗꦺꦴꦩ꧀ꦧꦁ) is a regency of East Java, Indonesia, situated to the southwest of Surabaya.

The regency is divided administratively into twenty-one districts (kecamatan), tabulated below with their areas and population totals from the 2010 census[2] and the 2020 census,[3] together with the official estimates as of mid-2023.

Note: (a) comprising 4 urban kelurahan (Jombatan, Jelakombo, Kaliwungu and Kepanjen) and 16 desa.

The five last-mentioned districts in the table constitute the folded limestone hilly region in the north, separated from the rest of the regency by the Brantas River.

The rest of the regency to the south of the river is more low-lying and constitutes good agricultural land, although the south-east corner (Ngoro, Mojowarno, Bareng and Wonosalam Districts) is more mountainous.