Barangay Casala

Classified as a small barangay, Barangay Casala is one of the administrative divisions of San Mariano in Isabela, Cagayan Valley, Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Casala had a population of 1,593. This made it the 19th largest of 36 barangays in San Mariano by population, placing it in the middle tier of the municipality. Residents of Barangay Casala accounted for approximately 2.65% of the total population of San Mariano, which stood at 60,124 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Casala moving from 1,507 residents to 1,593 residents, an intercensal change of +5.7%. The trajectory indicates a growing community. The Philippine Statistics Authority classifies Barangay Casala as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

San Mariano is a municipality comprising 36 barangays, and serves as the governing unit directly responsible for local services in Barangay Casala, including public health, sanitation, peace and order, and civil registration. Within the wider province of Isabela, which contains 1,055 barangays across its component cities and municipalities, Barangay Casala ranks 391st by 2020 population. Isabela is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

The barangay's legislative and executive affairs are handled by a Punong Barangay and the Sangguniang Barangay, elected nationwide during the Barangay and SK Elections. The next BSKE is scheduled for Monday, November 2, 2026, following the synchronized election schedule set by COMELEC Resolution No. 11191.