The Autonomous Region in Muslim Mindanao (abbreviated ARMM) is the region, located in the Mindanao island group of thePhilippines, that is composed of predominantly Muslim provinces, namely: Basilan (except Isabela City), Lanao del Sur, Maguindanao, Suluand Tawi-Tawi. It is the only region that has its own government. The regional capital is at Cotabato City, although this city is outside of its jurisdiction.

The ARMM previously included the province of Shariff Kabunsuan until 16 July 2008, when Shariff Kabunsuan ceased to exist as a provinceafter the Filipino Supreme Court declared the "Muslim Mindanao Autonomy Act 201", which created it, unconstitutional in Sema v. Comelec. On 7 October 2012, President Benigno Aquino III said that the government aimed to have peace in the region and it will be known as "Bangsamoro".

For the most part of the Philippines' history, the region and most of Mindanao has been a separate territory, which enabled it to develop its own culture and identity. The region has been the traditional homeland of Muslim Filipinos since the 15th century, even before the arrival of the Spanish who began to colonize most of the Philippines in 1565. Muslim missionaries arrived in Tawi-Tawi in 1380 and started the conversion of the native population to Islam. In 1457, the Sultanate of Sulu was founded, and not long after that the sultanates of Maguindanao and Buayan were also established. At the time when most of the Philippines was under Spanish rule, these sultanates maintained their independence and regularly challenged Spanish domination of the Philippinesby conducting raids on Spanish coastal towns in the north and repulsing repeated Spanish incursions in their territory. It was not until the last quarter of the 19th century that the Sultanate of Sulu formally recognized Spanish sovereignty, but these areas remained loosely controlled by the Spanish as their sovereignty was limited to military stations and garrisons and pockets of civilian settlements in Zamboanga and Cotabato, until they had to abandon the region as a consequence of their defeat in the Spanish-American War.

In 1942, during the early stages of Pacific War (a theater of the Second World War), troops of the Japanese Imperial Forces invaded and overran Mindanao. Three years later, in 1945, combined United States and Philippine Commonwealth Army troops liberated Mindanao, and with the help of local guerrilla units ultimately defeated the Japanese forces occupying the region.