Barangay San Isidro

Situated in Agoo, La Union, Barangay San Isidro is one of 49 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 San Isidro had a population of 2,324. This made it the 5th largest of 49 barangays in Agoo by population, placing it among the most populous barangays of the municipality. Residents of Barangay San Isidro accounted for approximately 3.52% of the total population of Agoo, which stood at 66,028 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay San Isidro changed from 2,082 to 2,324, a shift of +11.6% over the five-year period. This places the barangay among those with growing populations in Agoo. 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.

Agoo is a municipality comprising 49 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 73rd 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.