Barangay Tiagan

Situated in San Emilio, Ilocos Sur, Barangay Tiagan is one of 8 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 Tiagan had a population of 1,524. This made it the 1st largest of 8 barangays in San Emilio by population, placing it among the most populous barangays of the municipality. Residents of Barangay Tiagan accounted for approximately 21.15% of the total population of San Emilio, which stood at 7,206 in the same census year.

The barangay recorded 1,710 residents in the 2015 intercensal count and 1,524 residents in the 2020 Census — a net change of -10.9%, consistent with a contracting settlement. The Philippine Statistics Authority classifies Barangay Tiagan as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

San Emilio is a municipality comprising 8 barangays, and serves as the governing unit directly responsible for local services in Barangay Tiagan, 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 Tiagan ranks 99th 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.