Barangay Mabilbila Sur

Situated in Santa, Ilocos Sur, Barangay Mabilbila Sur is one of 26 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 Mabilbila Sur had a population of 1,996. This made it the 1st largest of 26 barangays in Santa by population, placing it among the most populous barangays of the municipality. Residents of Barangay Mabilbila Sur accounted for approximately 13.31% of the total population of Santa, which stood at 14,992 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Mabilbila Sur moving from 1,948 residents to 1,996 residents, an intercensal change of +2.5%. The trajectory indicates a growing community. The Philippine Statistics Authority classifies Barangay Mabilbila Sur as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Santa is a municipality comprising 26 barangays, and serves as the governing unit directly responsible for local services in Barangay Mabilbila Sur, including public health, sanitation, peace and order, and civil registration. Within the wider province of Ilocos Sur, which contains 768 barangays across its component cities and municipalities, Barangay Mabilbila Sur ranks 53rd by 2020 population. Ilocos Sur 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 Mabilbila 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.