Barangay Santo Rosario

Situated in Iba, Zambales, Barangay Santo Rosario is one of 14 barangays that make up the municipality within Central Luzon.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Santo Rosario had a population of 4,366. This made it the 6th largest of 14 barangays in Iba by population, placing it in the middle tier of the municipality. Residents of Barangay Santo Rosario accounted for approximately 7.86% of the total population of Iba, which stood at 55,581 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Santo Rosario moving from 3,979 residents to 4,366 residents, an intercensal change of +9.7%. The trajectory indicates a growing community. The Philippine Statistics Authority classifies Barangay Santo Rosario as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Iba is a municipality comprising 14 barangays, and serves as the governing unit directly responsible for local services in Barangay Santo Rosario, including public health, sanitation, peace and order, and civil registration. Within the wider province of Zambales, which contains 247 barangays across its component cities and municipalities, Barangay Santo Rosario ranks 36th by 2020 population. Zambales is classified as a 2nd by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Santo 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.