Maguindanao (Filipino: Magindanaw) is a province of the Philippines located in the Autonomous Region in Muslim Mindanao (ARMM). Its capital is Shariff Aguak. It borders Lanao del Sur to the north, Cotabato to the east, and Sultan Kudarat to the south.

Maguindanao is composed of 36 municipalities, which are further subdivided into 506 barangays. Cotabato City is often grouped with Maguindanao, but it is actually independent from the province.

The province is divided into two congressional districts. In October 2006, the first congressional district was split off into a new province, Shariff Kabunsuan. However, the ARMM's Act creating the province was nullified by the Supreme Court in July 2008, on the basis that creation of a province is a function of the Philippine legislature. The area has since reverted to the province of Maguindanao.

Maguindanao is divided into two congressional districts, which elect members to the House of Representatives. For the brief period that the province of Shariff Kabunsuan existed, Maguindanao became a lone-district province. Since the appointment of a new set of provincial officials for the reunified province of Maguindanao by the ARMM Governor in January 2009, the provincial government has reverted to the Sangguniang Panlalawigan setup (coterminous with the restored 1st and 2nd Congressional districts of Maguindanao) from before Shariff Kabunsuan was created.

Piang (1846–1933) popularly known as Datu Piang was a Maguindanao leader, often referred to as the Grand Old Man of Cotabato.

Datu Piang (sometimes referred to as Amai Mingka) was recognized as the undisputed Moro leader in Central Mindanao when the United States Army occupied and administered what was then referred to as "Moroland".