The legislative districts of Isabela are the representations of the province of Isabela and the independent component city of Santiago in the various national legislatures of the Philippines. The province and the city are currently represented in the lower house of the Congress of the Philippines through their first, second, third, fourth, fifth, and sixth congressional districts. History The province was represented as a lone legislative district until 1972. It was part of the representation of Region II from 1978 to 1984, and from 1984 to 1986, it elected 3 assemblymen at-large. In 1986, it was redistricted into four legislative districts. On September 27, 2018, President Rodrigo Duterte signed Republic Act No. 11080, increasing the legislative districts from four to six and reapportioned the district assignments of cities and municipalities. Six Districts (2019-Present) 1st District City: Ilagan Municipalities: Cabagan, Delfin Albano, Divilacan, Maconacon, San Pablo, Santa Maria, Santo Tomas, Tumauini Population (2020): 399,196 2nd District Municipalities: Benito Soliven, Gamu, Naguilian, Palanan, Reina Mercedes, San Mariano Population (2020): 199,903 3rd District Municipalities: Alicia, Angadanan, Cabatuan, Ramon, San Mateo Population (2020): 282,027 4th District City: Santiago Municipalities: Cordon, Dinapigue, Jones, San Agustin Population (2020): 268,602 5th District Municipalities: Aurora, Burgos, Luna, Mallig, Quezon, Quirino, Roxas, San Manuel Population (2020): 267,550 6th District City: Cauayan Municipalities: Echague, San Guillermo, San Isidro Population (2020): 279,772 Four Districts (1987-2019) 1st District City: Ilagan (became a city in 2012) Municipalities: Cabagan, Delfin Albano, Divilacan, Maconacon, Palanan, San Pablo, Santa Maria, Santo Tomas, Tumauini 2nd District Municipalities: Aurora, Benito Soliven, Burgos, Gamu, Mallig, Naguilian, Quezon, Quirino, Roxas, San Manuel, San Mariano 3rd District City: Cauayan (became a city in 2001) Municipalities: Alicia, Angadanan, Cabatuan, Luna, Reina Mercedes, San Guillermo, San Mateo 4th District City: Santiago (became a city in 1994) Municipalities: Cordon, Dinapigue, Echague, Jones, Ramon, San Agustin, San Isidro Notes Lone District (defunct) Notes At-Large (defunct) 1943–1944 1984–1986 References Isabela Politics of Isabela (province)