Barangay Casilagan

Classified as a small barangay, Barangay Casilagan is one of the administrative divisions of Mangatarem in Pangasinan, Ilocos Region, Philippines.

According to the 2020 Philippine census, Barangay Casilagan had a population of 1,701. This made it the 11th largest of 82 barangays in Mangatarem by population, placing it in the upper half of the municipality. Residents of Barangay Casilagan accounted for approximately 2.14% of the total population of Mangatarem, which stood at 79,323 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Casilagan changed from 1,399 to 1,701, a shift of +21.6% over the five-year period. This places the barangay among those with growing populations in Mangatarem. Barangay Casilagan is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Mangatarem is a municipality comprising 82 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 Pangasinan, which contains 1,364 barangays across its component cities and municipalities, Barangay Casilagan ranks 781st by 2020 population. Pangasinan is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Casilagan 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.