Kudus (Javanese: ꦏꦸꦢꦸꦱ꧀ Pegon: قدوس) is a regency (Indonesian: kabupaten) in Central Java province in Indonesia. Its capital is the town of Kudus. It covers 425.15 km and is thus the smallest regency on Java Island in area, and it had a population of 777,437 at the 2010 Census and 849,184 at the 2020 Census; the official estimate as at mid 2023 was 874,632, comprising 436,247 males and 438,385 females. It is located northeast of Semarang, the capital of Central Java.

The administrative boundaries of Kudus Regency include:

• North = Jepara Regency
• South = Grobogan Regency and Demak Regency
• West = Demak Regency
• East = Pati Regency

Most of the Kudus Regency area is lowland. In part of the northern region stands a mountain, namely Mount Muria, with the peaks Saptorenggo Peak (1,602 m above sea level), Rahtawu Peak (1,522 m above sea level), and Argojembangan Peak (1,410 m above sea level). The largest river is Kali Serang which flows to the west, bordering Kudus Regency with Demak Regency. Kudus is divided by the Gelis River in the middle so there are the terms Kudus West and Kudus East. Kudus Regency is the district with the smallest area in Central Java, but is the richest district in Central Java with per capita income reaching more than IDR 123 million.

The town of Kudus was something of an important Islamic holy city in the sixteenth century. It is the only place in Java that has permanently acquired an Arabic name ('al-Quds', Jerusalem). Sunan Kudus, one of the nine Wali Sanga, was said to have been the fifth imam (head) of the mosque of Demak and a major leader of the 1527 campaign against 'Majapahit', before moving to Kudus.

The Mosque of Kudus (Masjid Menara) which dates from this period, remains a local landmark to this day. It is notable for both its perseverance of pre-Islamic architectural forms such as Old Javanese split doorways and Hindu-Buddhist influenced Majapahit-style brickwork, and for its name al-Manar or al-Aqsa. The date AH 956 (AD 1549) is inscribed over the mihrab (niche indicating the direction of Mecca).

The Regency comprises nine districts (kecamatan), tabulated 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 number of administrative villages in each district (totaling 123 rural desa and 9 urban kelurahan - the latter all in Kudus town 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	Post code
33.19.01	Kaliwungu	32.71	91,174	103,293	107,367	Kedungdowo	15	59332
33.19.02	Kota Kudus (Kudus town)	10.47	92,776	89,480	89,700	Purwosari	25	59311 -59319
33.19.03	Jati	26.30	99,466	108,819	111,970	Tanjung Karang	14	59341 -59349
33.19.04	Undaan	71.77	69,073	76,128	77,409	Undaan Kidul	15	59372
33.19.05	Mejobo	36.77	69,754	77,434	80,014	Jepang	11	59381
33.19.06	Jekulo	82.92	98,741	108,658	111,995	Klaling	12	59382
33.19.07	Bae	23.32	66,333	73,903	76,446	Bae	10	59321 -59327
33.19.08	Gebog	55.06	93,915	104,313	107,806	Gondosari	11	59333
33.19.09	Dawe	85.84	96,205	106,685	110,206	Piji	18	59353
	Totals	425.15	777,437	849,184	874,632	Kudus (town)	132

Note: (a) comprises 9 urban kelurahan (Kajeksan, Kerjasan, Mlati Kidul, Mlati Norowito, Panjunan, Purwosari, Sunggingan, Wergu Kulon and Wergu Wetan) and 16 rural desa.
(b) Undaan District consists of a large southwards salient away from the rest of the Regency.

Although most residents of Kudus are Javanese, there is an Indonesian Chinese minority in the city center, as well as an Arab neighborhood, Kudus Kulon, to the west of the city center.

The city is considered the "birthplace" of the kretek clove cigarette, which is by far the most widely smoked form of tobacco in the country, and remains a major center for their manufacture. Haji Jamahri, a resident of the city, invented them in the 1880s. A festival named Dandangan is held for about one whole month before Ramadhan, Muslim's fasting month in Kudus Kulon.

On June 12, 2007, about 5,000 people gathered peacefully to protest against Jakarta's plan to build 4 nuclear reactors in the region. The movement included local residents, activists, artists, students and public officials, parliament members, military commandants and police chiefs. This movement has been part of a series of responses emerging from all sides of the Indonesian society against the use of nuclear technology for energy production.

• Hariyanto Arbi, badminton player
• Hermawan Susanto, badminton player
• Liem Swie King, badminton player
• Eddy Hartono, badminton player

• Sunan Kudus

• Minaret at Kudus - ArchNet.org