Barangay Buenavista

Situated in Castillejos, Zambales, Barangay Buenavista 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 Buenavista had a population of 851. This made it the 14th largest of 14 barangays in Castillejos by population, placing it among the smaller barangays of the municipality. Residents of Barangay Buenavista accounted for approximately 1.25% of the total population of Castillejos, which stood at 67,889 in the same census year.

The barangay recorded 850 residents in the 2015 intercensal count and 851 residents in the 2020 Census — a net change of +0.1%, consistent with a slowly expanding settlement. The Philippine Statistics Authority classifies Barangay Buenavista as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Castillejos is a municipality comprising 14 barangays, and serves as the governing unit directly responsible for local services in Barangay Buenavista, 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 Buenavista ranks 198th 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.

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.