The Legislative Districts of Isabela, namely the first, second, third, fourth districts, are the representations of the Province of Isabela and the independent city of Santiago in the Philippine House of Representatives. 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.