Maguindanao (Maguindanaoan: Dalapa sa Maguindanao; Cebuano: Lalawigan sa Maguindanao; Hiligaynon: Kapuoran sang Maguindanao; Chavacano: Provincia de Maguindanao; Filipino: Lalawigan ng Maguindanao) is a province in the Philippines located in the Autonomous Region in Muslim Mindanao (ARMM). Since 2014 the provincial capital is Buluan but the legislative branch of the provincial government, the Sangguniang Panlalawigan, convenes in the old provincial capitol in the town of Sultan Kudarat. It borders Lanao del Sur to the north, Cotabato to the east, Sultan Kudarat to the south, and the Illana Bay to the west.
Shariff Mohammed Kabungsuwan of Johore introduced Islam in the area at the end of the 15th century. He subsequently married a local princess from the Maranao Tribe of Malabang and Maguindanao Province, and established the Sultanate of Maguindanao. The Cotabato Valley formed the sultanate's heartland but its influence extended from the Zamboanga Peninsula to Sarangani Bay and Davao.