Barangay Tanglag

Situated in Rosario, La Union, Barangay Tanglag is one of 33 barangays that make up the municipality within Ilocos Region.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Tanglag had a population of 788. This made it the 29th largest of 33 barangays in Rosario by population, placing it among the smaller barangays of the municipality. Residents of Barangay Tanglag accounted for approximately 1.31% of the total population of Rosario, which stood at 60,278 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Tanglag changed from 743 to 788, a shift of +6.1% over the five-year period. This places the barangay among those with growing populations in Rosario. The Philippine Statistics Authority classifies Barangay Tanglag as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Rosario is a municipality comprising 33 barangays, and serves as the governing unit directly responsible for local services in Barangay Tanglag, 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 Tanglag ranks 442nd 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.