Barangay San Isidro

Barangay San Isidro is a small barangay in the municipality of Naguilian, located in the province of La Union, in the Ilocos Region region of the Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay San Isidro had a population of 899. This made it the 31st largest of 37 barangays in Naguilian by population, placing it among the smaller barangays of the municipality. Residents of Barangay San Isidro accounted for approximately 1.72% of the total population of Naguilian, which stood at 52,189 in the same census year.

The barangay recorded 933 residents in the 2015 intercensal count and 899 residents in the 2020 Census — a net change of -3.6%, consistent with a contracting settlement. The Philippine Statistics Authority classifies Barangay San Isidro as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Naguilian is a municipality comprising 37 barangays, and serves as the governing unit directly responsible for local services in Barangay San Isidro, 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 Isidro ranks 401st 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.

Like every Philippine barangay, Barangay San Isidro is led by an elected Punong Barangay (barangay captain) supported by seven Sangguniang Barangay members (kagawads), an SK Chairperson, a Barangay Secretary, and a Barangay Treasurer. The next Barangay and Sangguniang Kabataan Elections (BSKE) are scheduled for Monday, November 2, 2026, with officials serving four-year terms under Republic Act No. 12232.