They are ethnically and culturally closely related to the Maranao, and Maguindanaon, all three groups being denoted as speaking Danao languages and giving name to the island of Mindanao.

Iranun have also migrated to the west coast of Sabah, Malaysia (in which they are found in 25 villages around the Kota Belud and Lahad Datu districts).

They have also settled in Kudat and Likas, Kota Kinabalu, in which they assimilated with the Sama-Bajau, owing to their shared naval history as well as their common religious beliefs and same ancestral roots in the Bangsamoro region of the Southern Philippines.

For the duration of the 16th century, the Iranuns and Samal mercenaries were the initial core elements of the sultanate.

In the past, the seat of the Maguindanao Sultanate was situated at Lamitan (within modern-day Picong, Lanao del Sur) and T'bok, both of which were strongholds of the Iranun society.

Historically, the Iranun were given the exonym Ilanun (also spelled variously as Illanun, Illanoan, Illanoon, Ilanoon, etc.)