Barangay Santo Rosario

Barangay Santo Rosario forms part of San Juan, a municipality in La Union, and is classified as a small barangay.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Santo Rosario had a population of 835. This made it the 18th largest of 41 barangays in San Juan by population, placing it in the middle tier of the municipality. Residents of Barangay Santo Rosario accounted for approximately 2.06% of the total population of San Juan, which stood at 40,507 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Santo Rosario changed from 754 to 835, a shift of +10.7% over the five-year period. This places the barangay among those with growing populations in San Juan. The Philippine Statistics Authority classifies Barangay Santo Rosario as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

San Juan is a municipality comprising 41 barangays, and serves as the governing unit directly responsible for local services in Barangay Santo Rosario, 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 Santo Rosario ranks 427th 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 Santo Rosario 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.