The Ilanun or (Iranun) are very closely related culturally and linguistically to both the Maguindadaon and the Maranao. Sometimes the Ilanun (especially those living in Lanao del Sur) are counted with Maranao and sometimes with the Maguindanaon. But historically they have been a separate group, though all three groups sprang from common ethnic origins long centuries ago. The Maguindanaon word "Manawen (people from the lake) is suggestive as the original from of the name "Ilanun".
The Ilanun are primarily concentrated along Illana Bay coast, north of the mouth of the Pulangi River all the way to Sibugay Bay in Zamboanga del Sur. They are active traders and historically they were great buccaneers. They have their own datus but in the past they more or less acknowledged the over-lord ship of the Sultan of Maguindanao. Most of them engaged in fishing white the rest raise food crops.