Barangay San Eustacio

Barangay San Eustacio forms part of Aliaga, a municipality in Nueva Ecija, and is classified as a mid-sized barangay.

According to the 2020 Philippine census, Barangay San Eustacio had a population of 2,355. This made it the 14th largest of 26 barangays in Aliaga by population, placing it in the middle tier of the municipality. Residents of Barangay San Eustacio accounted for approximately 3.35% of the total population of Aliaga, which stood at 70,363 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay San Eustacio changed from 1,731 to 2,355, a shift of +36.0% over the five-year period. This places the barangay among those with growing populations in Aliaga. Barangay San Eustacio is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Aliaga is a municipality comprising 26 barangays, and serves as the governing unit directly responsible for local services in Barangay San Eustacio, including public health, sanitation, peace and order, and civil registration. Within the wider province of Nueva Ecija, which contains 849 barangays across its component cities and municipalities, Barangay San Eustacio ranks 363rd by 2020 population. Nueva Ecija is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay San Eustacio is governed by an elected Sangguniang Barangay composed of a Punong Barangay and seven kagawads, with the Sangguniang Kabataan representing the youth. The next BSKE, set for Monday, November 2, 2026, will elect officials to four-year terms as provided under Republic Act No. 12232.