Barangay San Agustin

Situated in Aroroy, Masbate, Barangay San Agustin is one of 41 barangays that make up the municipality within Bicol Region.

According to the 2020 Philippine census, Barangay San Agustin had a population of 1,820. This made it the 18th largest of 41 barangays in Aroroy by population, placing it in the middle tier of the municipality. Residents of Barangay San Agustin accounted for approximately 2.06% of the total population of Aroroy, which stood at 88,351 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay San Agustin changed from 1,857 to 1,820, a shift of -2.0% over the five-year period. This places the barangay among those with broadly stable populations in Aroroy. Barangay San Agustin is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Aroroy is a municipality comprising 41 barangays, and serves as the governing unit directly responsible for local services in Barangay San Agustin, including public health, sanitation, peace and order, and civil registration. Within the wider province of Masbate, which contains 550 barangays across its component cities and municipalities, Barangay San Agustin ranks 160th by 2020 population. Masbate is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

The barangay's legislative and executive affairs are handled by a Punong Barangay and the Sangguniang Barangay, elected nationwide during the Barangay and SK Elections. The next BSKE is scheduled for Monday, November 2, 2026, following the synchronized election schedule set by COMELEC Resolution No. 11191.