Barangay San Marcos

Classified as a small barangay, Barangay San Marcos is one of the administrative divisions of Sarrat in Ilocos Norte, Ilocos Region, Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay San Marcos had a population of 1,403. This made it the 6th largest of 24 barangays in Sarrat by population, placing it in the upper half of the municipality. Residents of Barangay San Marcos accounted for approximately 5.57% of the total population of Sarrat, which stood at 25,186 in the same census year.

The barangay recorded 1,377 residents in the 2015 intercensal count and 1,403 residents in the 2020 Census — a net change of +1.9%, consistent with a slowly expanding settlement. The Philippine Statistics Authority classifies Barangay San Marcos as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Sarrat is a municipality comprising 24 barangays, and serves as the governing unit directly responsible for local services in Barangay San Marcos, including public health, sanitation, peace and order, and civil registration. Within the wider province of Ilocos Norte, which contains 559 barangays across its component cities and municipalities, Barangay San Marcos ranks 130th by 2020 population. Ilocos Norte is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay San Marcos 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.