Barangay Rosario

Barangay Rosario forms part of City of Santiago, a city in Isabela, and is classified as a large barangay.

According to the 2020 Philippine census, Barangay Rosario had a population of 12,399. This made it the 2nd largest of 37 barangays in City of Santiago by population, placing it among the most populous barangays of the city. Residents of Barangay Rosario accounted for approximately 8.34% of the total population of City of Santiago, which stood at 148,580 in the same census year.

The barangay recorded 11,441 residents in the 2015 intercensal count and 12,399 residents in the 2020 Census — a net change of +8.4%, consistent with a growing settlement. Barangay Rosario is officially classified as urban, reflecting the density and built-up character of the area.

City of Santiago is a city comprising 37 barangays, and serves as the governing unit directly responsible for local services in Barangay Rosario, including public health, sanitation, peace and order, and civil registration. Within the wider province of Isabela, which contains 1,055 barangays across its component cities and municipalities, Barangay Rosario ranks 2nd by 2020 population. Isabela is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Rosario 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.