Barangay San Nicolas Sur (Pob.)

Situated in Agoo, La Union, Barangay San Nicolas Sur (Pob.) is one of 49 barangays that make up the municipality within Ilocos Region.

According to the 2020 Philippine census, Barangay San Nicolas Sur (Pob.) had a population of 511. This made it the 49th largest of 49 barangays in Agoo by population, placing it among the smaller barangays of the municipality. Residents of Barangay San Nicolas Sur (Pob.) accounted for approximately 0.77% of the total population of Agoo, which stood at 66,028 in the same census year.

The barangay recorded 485 residents in the 2015 intercensal count and 511 residents in the 2020 Census — a net change of +5.4%, consistent with a growing settlement. Barangay San Nicolas Sur (Pob.) is officially classified as urban, reflecting the density and built-up character of the area.

Agoo is a municipality comprising 49 barangays, and serves as the governing unit directly responsible for local services in Barangay San Nicolas Sur (Pob.), 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 Nicolas Sur (Pob.) ranks 531st 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 Nicolas Sur (Pob.) 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.