Located in the southern region of the archipelago, as of the 2010 census, the main island was inhabited by 20,281,545 people, while the entire Mindanao island group had an estimated total of 25,537,691 (2018) residents.
According to the 2015 Philippine Population Census, Davao City is the most populous city on the island, with a population of 1,632,991 residents, followed by Zamboanga City (pop. 861,799), Cagayan de Oro City (pop. 675,950), General Santos City (pop. 594,446), Iligan City (pop. 342,618), Butuan City (pop. 337,063) and Cotabato City (pop. 299,438). About 70% of residents identify as Christian, and 20% identify as Muslim. Mindanao is divided into six regions: the Zamboanga Peninsula, Northern Mindanao, the Caraga region, the Davao region, Soccsksargen, and the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM).
Native ethnic groups in Mindanao include the Lumads (namely the Subanons of the Zamboanga Peninsula; the Bukidnon, the Ata Manobos, the Mamanwas, the Matigsalugs, the Agusan Manobos, the Talaandigs, the Kamigins, and the Higaonons of Northern Mindanao and the region of Caraga; the T’bolis, the Tirurays, the B’laans, the Sarangani, and the Cotabato Manobos of the region of SOCCSKSARGEN; and the Obo, the Mandayas, the Giangans, the Tagabawas, the Kalagans, the Sangirese, and the Mansaka of the Davao region) and the Moros (namely the Maguindanaos, the Maranaos, the Tausugs, the Yakans, the Iranuns, and the Sama, mainly concentrated within the Autonomous Region in Muslim Mindanao (ARMM). Joining them are the equally indigenous Butuanons and the Surigaonons of the Caraga region as well as the Zamboangueños of the eponymous peninsula, along with descendants of settlers from the Visayas and Luzon (chiefly from the former), among them the Cebuanosand the Hiligaynons.