Barangay Aglao

Barangay Aglao is a mid-sized barangay in the municipality of San Marcelino, located in the province of Zambales, in the Central Luzon region of the Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Aglao had a population of 2,380. This made it the 7th largest of 18 barangays in San Marcelino by population, placing it in the middle tier of the municipality. Residents of Barangay Aglao accounted for approximately 6.31% of the total population of San Marcelino, which stood at 37,719 in the same census year.

The barangay recorded 1,939 residents in the 2015 intercensal count and 2,380 residents in the 2020 Census — a net change of +22.7%, consistent with a growing settlement. The Philippine Statistics Authority classifies Barangay Aglao as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

San Marcelino is a municipality comprising 18 barangays, and serves as the governing unit directly responsible for local services in Barangay Aglao, including public health, sanitation, peace and order, and civil registration. Within the wider province of Zambales, which contains 247 barangays across its component cities and municipalities, Barangay Aglao ranks 92nd by 2020 population. Zambales is classified as a 2nd by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Like every Philippine barangay, Barangay Aglao 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.