Barangay Antagan

Situated in Santo Tomas, Isabela, Barangay Antagan is one of 27 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 Antagan had a population of 500. This made it the 22nd largest of 27 barangays in Santo Tomas by population, placing it among the smaller barangays of the municipality. Residents of Barangay Antagan accounted for approximately 2.04% of the total population of Santo Tomas, which stood at 24,528 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Antagan moving from 491 residents to 500 residents, an intercensal change of +1.8%. The trajectory indicates a slowly expanding community. The Philippine Statistics Authority classifies Barangay Antagan as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Santo Tomas is a municipality comprising 27 barangays, and serves as the governing unit directly responsible for local services in Barangay Antagan, 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 Antagan ranks 940th 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.