The lone Legislative District of Maguindanao del Sur is the representation of the province of Maguindanao del Sur in the Philippine House of Representatives.
341 on November 22, 1973, created the province of Maguindanao out of Cotabato's Maguindanao-majority municipalities.
[1] The new province was represented in the Interim Batasang Pambansa as part of Region XII from 1978 to 1984.
Maguindanao del Sur first gained separate representation in 1984, when it returned two representatives, elected at large, to the Regular Batasang Pambansa.
Under the new Constitution which was proclaimed on February 11, 1987, Maguindanao del Sur, was retained into one congressional district;[2] each elected its member to the restored House of Representatives starting that same year.