Barangay Gusing Sur

Barangay Gusing Sur forms part of Naguilian, a municipality in La Union, and is classified as a small barangay.

According to the 2020 Philippine census, Barangay Gusing Sur had a population of 1,427. This made it the 13th largest of 37 barangays in Naguilian by population, placing it in the middle tier of the municipality. Residents of Barangay Gusing Sur accounted for approximately 2.73% of the total population of Naguilian, which stood at 52,189 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Gusing Sur changed from 1,622 to 1,427, a shift of -12.0% over the five-year period. This places the barangay among those with contracting populations in Naguilian. Barangay Gusing Sur is officially classified 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 Gusing Sur, 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 Gusing Sur ranks 211th 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 Gusing Sur 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.