Barangay Santo Tomas

Barangay Santo Tomas is a very small barangay in the municipality of Santo Domingo, located in the province of Ilocos Sur, in the Ilocos Region region of the Philippines.

According to the 2020 Philippine census, Barangay Santo Tomas had a population of 438. This made it the 31st largest of 36 barangays in Santo Domingo by population, placing it among the smaller barangays of the municipality. Residents of Barangay Santo Tomas accounted for approximately 1.51% of the total population of Santo Domingo, which stood at 29,041 in the same census year.

The barangay recorded 439 residents in the 2015 intercensal count and 438 residents in the 2020 Census — a net change of -0.2%, consistent with a broadly stable settlement. Barangay Santo Tomas is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Santo Domingo is a municipality comprising 36 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 Ilocos Sur, which contains 768 barangays across its component cities and municipalities, Barangay Santo Tomas ranks 627th by 2020 population. Ilocos Sur 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.