Barangay Castro

Classified as a small barangay, Barangay Castro is one of the administrative divisions of Sudipen in La Union, Ilocos Region, Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Castro had a population of 1,725. This made it the 1st largest of 17 barangays in Sudipen by population, placing it among the most populous barangays of the municipality. Residents of Barangay Castro accounted for approximately 10.04% of the total population of Sudipen, which stood at 17,187 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Castro changed from 1,550 to 1,725, a shift of +11.3% over the five-year period. This places the barangay among those with growing populations in Sudipen. The Philippine Statistics Authority classifies Barangay Castro as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Sudipen is a municipality comprising 17 barangays, and serves as the governing unit directly responsible for local services in Barangay Castro, 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 Castro ranks 139th 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.

Barangay Castro is governed by an elected Sangguniang Barangay composed of a Punong Barangay and seven kagawads, with the Sangguniang Kabataan representing the youth. The next BSKE, set for Monday, November 2, 2026, will elect officials to four-year terms as provided under Republic Act No. 12232.