Barangay Santo Tomas

Barangay Santo Tomas is a small barangay in the municipality of Naguilian, located in the province of Isabela, in the Cagayan Valley region of the Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Santo Tomas had a population of 804. This made it the 15th largest of 25 barangays in Naguilian by population, placing it in the middle tier of the municipality. Residents of Barangay Santo Tomas accounted for approximately 2.38% of the total population of Naguilian, which stood at 33,788 in the same census year.

The barangay recorded 701 residents in the 2015 intercensal count and 804 residents in the 2020 Census — a net change of +14.7%, consistent with a growing settlement. The Philippine Statistics Authority classifies Barangay Santo Tomas as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Naguilian is a municipality comprising 25 barangays, and serves as the governing unit directly responsible for local services in Barangay Santo Tomas, 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 Santo Tomas ranks 766th 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.

Like every Philippine barangay, Barangay Santo Tomas is led by an elected Punong Barangay (barangay captain) supported by seven Sangguniang Barangay members (kagawads), an SK Chairperson, a Barangay Secretary, and a Barangay Treasurer. The next Barangay and Sangguniang Kabataan Elections (BSKE) are scheduled for Monday, November 2, 2026, with officials serving four-year terms under Republic Act No. 12232.