Barangay Calaoagan

Situated in San Guillermo, Isabela, Barangay Calaoagan is one of 26 barangays that make up the municipality within Cagayan Valley.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Calaoagan had a population of 447. This made it the 21st largest of 26 barangays in San Guillermo by population, placing it among the smaller barangays of the municipality. Residents of Barangay Calaoagan accounted for approximately 2.14% of the total population of San Guillermo, which stood at 20,915 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Calaoagan changed from 411 to 447, a shift of +8.8% over the five-year period. This places the barangay among those with growing populations in San Guillermo. The Philippine Statistics Authority classifies Barangay Calaoagan as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

San Guillermo is a municipality comprising 26 barangays, and serves as the governing unit directly responsible for local services in Barangay Calaoagan, 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 Calaoagan ranks 974th 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.

Barangay Calaoagan 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.