Barangay Al-alinao Sur

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

According to the 2020 Philippine census, Barangay Al-alinao Sur had a population of 997. This made it the 27th largest of 37 barangays in Naguilian by population, placing it among the smaller barangays of the municipality. Residents of Barangay Al-alinao Sur accounted for approximately 1.91% of the total population of Naguilian, which stood at 52,189 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Al-alinao Sur moving from 982 residents to 997 residents, an intercensal change of +1.5%. The trajectory indicates a slowly expanding community. Barangay Al-alinao 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 Al-alinao 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 Al-alinao Sur ranks 355th 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 Al-alinao 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.