Madiun (Javanese: ꦑꦸꦛꦩꦝꦶꦪꦸꦤ꧀, romanized: Kutha Madhiun) is a city in the western part of East Java, Indonesia, known for its agricultural center. The city has been administratively separate from the surrounding Madiun Regency since the formation of the two bodies in 1950, but the city remained the seat of the regency administration until 2010. Madiun is commonly known as "Kota Gadis", which is an acronym for "Trading, Education and Industrial City" in Indonesian and sometimes known as Milaan van Java in Dutch language.

Madiun, located 169 kilometres (105 mi) southwest of Surabaya and 38 kilometres (24 mi) southeast of Ngawi, covers an area of 33.23 square kilometres (12.83 sq mi), and had a population of 170,964 at the 2010 Census and 195,175 at the 2020 Census; the latest official estimate (as of mid 2023) is 202,544 (comprising 99,319 males and 103,225 females). This city is an average of 63 metres (207 ft) above sea level and lies on the Madiun River, a tributary of the Bengawan Solo River. It is surrounded by a number of mountains, including Mount Wilis (2,169 m (7,116 ft)) to the east, to the south the Kapur Selatan range (500–1,000 m (1,600–3,300 ft)) and to the west Mount Lawu (3,285 m (10,778 ft)). Madiun has an average temperature of 20–35 °C (68–95 °F).

The city is divided into three districts (kecamatan), tabulated below with their areas and their population totals from the 2010 Census and 2020 Census, together with the official estimates for mid 2023. The table also includes the locations of the district administrative centres, the number of administrative villages (urban kelurahan) in each district, and its postal codes.

Kode Wilayah	Name of District (kecamatan)	Area in km	Pop'n census 2010	Pop'n census 2020	Pop'n estimate mid 2023	No. of villages	Post codes
35.77.02	Manguharjo	10.04	48,906	57,779	60,359	9	63121-63129
35.77.03	Taman	12.46	72,667	83,698	86,149	9	63131-63139
35.77.01	Kartoharjo	10.73	49,391	53,698	56,036	9	63111-63119
	Totals	33.23	170,964	195,175	202,544	27

The names of the kelurahan in each district are :

• Manguharjo : Madiun Lor, Manguharjo, Nambangan Kidul, Nambangan Lor, Ngegong, Pangongangan, Patihan, Sogaten, Winongo
• Taman : Banjarejo, Demangan, Josenan, Kejuron, Kuncen, Mojorejo, Manisrejo, Pandean, Taman
• Kartoharjo : Kanigoro, Kelun, Kartoharjo, Klegen, Oro-Oro Ombo, Pilangbango, Rejomulyo, Sukosari, Tawangrejo

Madiun was the site of a noted uprising in 1948 by elements of the Communist Party of Indonesia (PKI), the "Madiun Affair". After the signing of the Renville Agreement that year, guerrilla units and militias under the influence of PKI were ordered to disband. In Madiun a group of PKI militia refused to disarm and were killed in September. The killings sparked a violent uprising. Army sources claimed that the PKI had announced the proclamation of the "Soviet Republic of Indonesia" on 18 September with Musso as its president and Amir Sjarifuddin as its prime minister.

The uprising was suppressed by republican troops. On 30 September, Madiun was taken over by republican troops of the Silwangi Division. Thousands of party cadres were killed and 36,000 were imprisoned. Amongst the executed PKi members were several leaders including Muso killed on 31 October, allegedly while trying to escape from prison. Other PKI leaders such as D.N. Aidit went into exile in China.

Madiun has a tropical monsoon climate (Am) with moderate to little rainfall from June to October and heavy rainfall from November to May.

Madiun is served by Madiun railway station.

• Madiun Affair
• Indonesian National Revolution

• (in Indonesian) Official site
• (in English) Map of Madiun and surrounding area
• Highest University in Madiun