Santiago, officially the City of Santiago, is an independent component city in the Cagayan Valley region of the Philippines. It is not part of any province for administrative purposes, though it is grouped with the province of Isabela for statistical and geographic purposes.
According to the 2024 census, Santiago has a population of 150,313 people. As an independent component city, it maintains its own local government and is not under the jurisdiction of the provincial government of Isabela.