Ilagan, belonging to the 1st Legislative District of the Province of Isabela, is governed by a City Mayor designated as its Local Chief Executive and by a City Council as its Legislative body in accordance with the Local Government Code. The City Mayor, City Vice Mayor, and the City Councilors are elected directly by the people through an election which is being held every three (3) years.

As component city of the Province of Isabela, government officials are voted by the residents of the city. The provincial government still have political jurisdiction over local transactions of the city government.

Position Name
District Representative
(1st Legislative District of the Province of Isabela)
Antonio T. Albano
Chief Executive Mayor Josemarie L. Diaz
Presiding Officer Vice Mayor Kiryll S. Bello
Councilors Jay Eveson C. Diaz
 Jessamyn Uy Ligan
 Rachelle Villanueva Garcia
 Harold P. Olalia
 Antonio R. Montereal, Jr.
 Lilian Q. Bringas
 Joey L. Ramos
 Rolando L. Tugade
 Rommel B. Ballesteros
 Daniel Joseph A. Mata

There were 28 municipal mayors during its municipal period since 1904. Its first city mayor is Josemarie L. Diaz, DMD from 2012–2016.

Ilagan City is politically subdivided into 91 barangays, the most barangays in the province. Each barangay consist of 7 puroks and some have sitios. Currently, there are 12 barangays in the city that are considered urban.

Barangays in Ilagan City are grouped into 4 clusters, namely Centro Poblacion Cluster, Northeastern Cluster, San Antonio Cluster, and Western Cluster. (Click here to see list of 91 Barangays)