Madiun Regency (Indonesian: Kabupaten Madiun; Javanese: ꦩꦢꦶꦪꦸꦤ꧀) is a landlocked Regency in East Java province, Indonesia. It covers an area of 1,113.63 km², and had a population of 662,278 at the 2010 Census and 744,350 at the 2020 Census; the official estimate as at mid 2024 was 737,875 (comprising 365,305 males and 372,570 females). It is bordered by Bojonegoro Regency in the north, Nganjuk Regency in the east, Ponorogo Regency in the south, and Magetan Regency and Ngawi Regency in the west, while the independent city of Madiun (not included in the above figures) is an enclave within the regency.

Its capital was formerly the city of Madiun, but it was moved to Mejayan District by Government Regulation No.52 in 2010. However, Government Regulation No.3 of the Year 2019, as a revision of Government Regulation No. 52 of the year 2010, mentions that the capital of Madiun Regency is now called "Caruban", not Mejayan.

Most government buildings are located in areas that are part of the Caruban District. Other buildings will be moved gradually from the City of Madiun and the move began in 2011. In everyday conversation, Madiun Regency residents use the Javanese language with the dialect or dialects of Mataraman Madiun which is more inclined to accent Surakarta/Sala.

Madiun Regency consists of fifteen districts (kecamatan), tabulated below with their areas and population totals from the 2010 Census and the 2020 Census, together with the official estimates as at mid-2024. The table also includes the location of the district administrative centres, the number of administrative villages in each district (totaling 198 rural desa and eight urban kelurahan), and its postal codes.

Note: (a) including 2 kelurahan (Bangunsari and Milir). (b) including 2 kelurahan (Munggut and Wungu).
(c) comprising 3 kelurahan (Bangunsari, Krajan and Pandean) and 11 desa.
(d) except for the village of Sidodadi, which has a postcode of 63112.
(e) including one kelurahan (Nglamas).

Madiun is an area pioneered by Ki Panembahan Ronggo Jumeno, also called Ki Ageng Ronggo. The origin of the word "Madiun" is medi (ghost) and ayun-ayun (swing), the point is that when Ronggo Jumeno does "Tripe Madiun land" many ghosts wander around. A second explanation for the name keris owned by Ronggo Jumeno, is named Kris Tundhung Medhiun. At first not named Madiun, but Wonoasri.

Since the beginning, Madiun has been a territory under the control of the Sultanate of Mataram. In the course of the history of Mataram, Madiun is very strategically located in the region since the middle of the border with the kingdom of Kadiri (Daha). Therefore, during the reign of many rebels Mataram kingdom built a power base in Madiun. As the emergence of figures Retno Dumilah.

Some relics of the Duchy of Madiun one of which can be seen in the Village Kuncen, where there is the tomb of Ki Ageng Panembahan Ronggo Jumeno, Patih Wonosari besides the graves of the Regent Madiun, Madiun's oldest mosque is Masjid Nur Hidayatullah, artifacts around the mosque, and spring (bathing place) sacred.