Barangay San Martin

Classified as a small barangay, Barangay San Martin is one of the administrative divisions of Bacnotan in La Union, Ilocos Region, Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay San Martin had a population of 940. This made it the 19th largest of 47 barangays in Bacnotan by population, placing it in the middle tier of the municipality. Residents of Barangay San Martin accounted for approximately 2.12% of the total population of Bacnotan, which stood at 44,388 in the same census year.

The barangay recorded 810 residents in the 2015 intercensal count and 940 residents in the 2020 Census — a net change of +16.0%, consistent with a growing settlement. The Philippine Statistics Authority classifies Barangay San Martin as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Bacnotan is a municipality comprising 47 barangays, and serves as the governing unit directly responsible for local services in Barangay San Martin, including public health, sanitation, peace and order, and civil registration. Within the wider province of La Union, which contains 576 barangays across its component cities and municipalities, Barangay San Martin ranks 381st by 2020 population. La Union 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.