The Spanish encomienderos came to Iguig were well impressed by the friendliness displayed by the natives of the place and their willingness to embrace Christianity.
In honor of the towns chieftain who was popularly called "Ig", the Spanish authorities named it Iguig.
Fray Ambrocio dela Madre de Dios, O.P. and Fray Juan Layba, O.P. spearheaded the ground-breaking ceremony in the construction of the first parish church in the area. The first three churches built were washed away by great floods. And finally the fourth was built on a high hill where it is now with San Tiago as patron saint.
The Ilokanos begin to settle in Iguig in the early part of the year 1608. A cholera epidemic in 1898 decimated the population and a conflagration reduced to ashes almost all the houses in the town.
During the outbreak of the second World War, the people fled to the hills. The municipal officials who refused to serve the Japanese government went to Tuao where the Resistance Government of Governor Marcelo Adduru was functioning. After the wartime, the evacuees returned to their homes and started a new life. The struggle to rehabilitate was eased by war damage payments.
Today, Iguig, though only a small town, is conspicous to commuters along the Maharlika Highway with its great land markers: the Iguig historic centuries-old parish church on the hill and the popular tourist attraction, the Iguig Calvary in which the 14 Stations of the Cross are depicted in life-size concrete monuments; the mildew-coated Rectory well constructed in 1768 which was then the only source of drinking water and the brick stairway to the west of the church. This stairway was used for visiting Spanish dignitaries who travelled aboard barangays (banca) which plied up and down the river.