Barangay Casilagan

Barangay Casilagan forms part of Bauang, a municipality in La Union, and is classified as a small barangay.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Casilagan had a population of 1,184. This made it the 31st largest of 39 barangays in Bauang by population, placing it among the smaller barangays of the municipality. Residents of Barangay Casilagan accounted for approximately 1.51% of the total population of Bauang, which stood at 78,449 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Casilagan moving from 1,104 residents to 1,184 residents, an intercensal change of +7.2%. The trajectory indicates a growing community. The Philippine Statistics Authority classifies Barangay Casilagan as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Bauang is a municipality comprising 39 barangays, and serves as the governing unit directly responsible for local services in Barangay Casilagan, including public health, sanitation, peace and order, and civil registration. Within the wider province of La Union, which contains 576 barangays across its component cities and municipalities, Barangay Casilagan ranks 282nd by 2020 population. La Union 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.