Barangay San Mariano

Situated in Santa Rosa, Nueva Ecija, Barangay San Mariano is one of 33 barangays that make up the municipality within Central Luzon.

According to the 2020 Philippine census, Barangay San Mariano had a population of 1,693. This made it the 24th largest of 33 barangays in Santa Rosa by population, placing it in the middle tier of the municipality. Residents of Barangay San Mariano accounted for approximately 2.24% of the total population of Santa Rosa, which stood at 75,649 in the same census year.

Census comparisons between 2015 and 2020 show Barangay San Mariano moving from 1,765 residents to 1,693 residents, an intercensal change of -4.1%. The trajectory indicates a contracting community. Barangay San Mariano is officially classified as urban, reflecting the density and built-up character of the area.

Santa Rosa is a municipality comprising 33 barangays, and serves as the governing unit directly responsible for local services in Barangay San Mariano, 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 Mariano ranks 523rd 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 Mariano 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.