The Ilanun (Iranun, Ilianon, Ilanum, Hilanoones, Ilanos) are a group related to the Maranao and the Magindanao. They are found in the province of Magindanao in the municipalities of Nulingi (15,175), Parang (8,045), Matanog (5,595), and Barira (5,650) (NSO 1980)—the area about Polloc Harbor and Illana Bay east of Zamboanga and traditionally to the foothills of the Tiruray highlands; with a population of over 149,683 (NM 1994). The major concentration of the people is now along the coastline. There is a remnant group called Ilanun of over 4,000 people on the western coastal plain of North Borneo. The Ilanun differentiated from the Maranao and Magindanao populations prior to the introduction of Islam into the area, remaining distributed along the waterways and coasts with a major development in the area between Balabagan and Malabang.

       The people, who are marine-oriented, are historically known for their sea exploits. Spanish pressures forced the Ilanun inland and forced them to the sanctuary of the Lake Lanao area from which they shifted their operations. The area became so important that the Spaniards tended to think that the Ilanun are from Lanao del Sur. The withdrawal of the Spaniards led to the lessening of contact between the Maranao and the Ilanun. At present, the culture is generally similar to the Maranao of Lanao del Sur province with a subsistence pattern based on intensive wet cultivation of rice, long distance marine trade, and fishing.