Maguindanao's 1st congressional district was one of the two congressional districts of the Philippines in the province of Maguindanao.

[3] The district stretched along the Moro Gulf coast of western Maguindanao and includes Cotabato City, an independent port city.

Barira, Buldon, Datu Blah T. Sinsuat, Datu Odin Sinsuat, Kabuntalan, Matanog, Northern Kabuntalan, Parang, Sultan Kudarat, Sultan Mastura and Upi are the district's constituent municipalities.

[4] From 2006 to 2008, the district was briefly replaced by the lone district of Shariff Kabunsuan, a short-lived province that was carved out of the same area in Maguindanao and which was eventually nullified by the Supreme Court.

It was last represented in the 19th Congress by Sittie Shahara Mastura of Lakas-CMD, who was later redistricted to at-large district of the newly established province of Maguindanao del Norte in 2022.