Iligan has a total land area of 813.37 km2 (314.04 sq mi), making it one of the 10 largest cities in the Philippines in terms of land area. It has an estimated population of 322,821 inhabitants as of 2010.
Iligan City had its beginnings in the village of Bayug, four (4) kilometers north of the present Poblacion. It was the earliest pre-Spanish settlement of native sea dwellers. The monotony of indigenous life in the territory was broken when in the later part of the 16th century, the inhabitants were subdued by the Visayan migrants from the island kingdom of Panglao.
In Dapitan, the surviving Prince of Panglao Pagbuaya, received Legazpi's expedition in 1565. Later, Pagbuaya's son Manook was baptized Pedro Manuel Manook. The Christianized Manook subdued the Higaunon village in Bayug and established it as one of the earliest Christian settlements in the country. The settlement survived other raids from other enemies, and, because of their faith in God and in their patron saint, Saint Michael the Archangel, the early Iliganons moved their settlement from Bayug to Iligan.
A stone fort called Fort St. Francis Xavier was built in 1642 where Iliganons sought refuge during raids by bandits. But again, the fort sank due to floods. Another fort was built and this was named Fort Victoria or Cota de Iligan.
In 1850, because of floods, Don Remigio Cabili, then Iligan's governadorcillo, built another fort and moved the poblacion of the old Iligan located at the mouth of Tubod River west of the old market to its present site.
Iligan was already a town of the once undivided Misamis Province in 1832. However, it did not have an independent religious administration because it was part of Cagayan de Oro, the provincial capital. It was one of the biggest municipalities of Misamis Province.
The Spaniards abandoned Iligan in 1899, paving the way for the landing of the American forces in 1900.
In 1903, the Moro Province was created. Iligan, because of its Moro residents was taken away from the Misamis Province. Then Iligan became the capital of the Lanao District and seat of the government where the American officials lived and held office. Later in 1907 the capital of the Lanao District was transferred to Dansalan.
In 1914, under the restructuring of Moroland after the end of the Moro Province (1903–1913), Iligan became a municipality composed of eight barrios together with the municipal district of Mandulog. After enjoying peace and prosperity for about 40 years, Iligan was invaded by Japanese forces in 1942.
The liberation in Iligan by the Philippine Commonwealth forces attacked by the Japanese held sway in the city until 1944 to 1945 when the war ended. On November 15, 1944, the city held a Commonwealth Day parade to celebrate the end of Japanese atrocities and occupation.
Using the same territorial definition as a municipality, Iligan became a chartered city of Lanao del Norte on June 16, 1950. It was declared a first class city in 1969 and was reclassified as First Class City "A" on July 1, 1977 by virtue of Presidential Decree No. 465. In 1983, Iligan was again reclassified as a highly urbanized city.
REPUBLIC ACT No. 9724, an Act separating the City of Iligan from the First Legislative District of the Province of Lanao del Norte was approved by Pres. Gloria Macapagal Arroyo last October 20, 2009.