Barangay San Agustin

Classified as a very small barangay, Barangay San Agustin is one of the administrative divisions of Gumaca in Quezon, CALABARZON, Philippines.

According to the 2020 Philippine census, Barangay San Agustin had a population of 196. This made it the 54th largest of 59 barangays in Gumaca by population, placing it among the smaller barangays of the municipality. Residents of Barangay San Agustin accounted for approximately 0.27% of the total population of Gumaca, which stood at 71,942 in the same census year.

The barangay recorded 179 residents in the 2015 intercensal count and 196 residents in the 2020 Census — a net change of +9.5%, consistent with a growing settlement. Barangay San Agustin is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Gumaca is a municipality comprising 59 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 Quezon, which contains 1,242 barangays across its component cities and municipalities, Barangay San Agustin ranks 1180th by 2020 population. Quezon 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.