Barangay Alagao

Barangay Alagao is a mid-sized barangay in the municipality of San Ildefonso, located in the province of Bulacan, in the Central Luzon region of the Philippines.

According to the 2020 Philippine census, Barangay Alagao had a population of 3,607. This made it the 13th largest of 36 barangays in San Ildefonso by population, placing it in the middle tier of the municipality. Residents of Barangay Alagao accounted for approximately 3.12% of the total population of San Ildefonso, which stood at 115,713 in the same census year.

Census comparisons between 2015 and 2020 show Barangay Alagao moving from 3,506 residents to 3,607 residents, an intercensal change of +2.9%. The trajectory indicates a growing community. Barangay Alagao is officially classified as urban, reflecting the density and built-up character of the area.

San Ildefonso is a municipality comprising 36 barangays, and serves as the governing unit directly responsible for local services in Barangay Alagao, including public health, sanitation, peace and order, and civil registration. Within the wider province of Bulacan, which contains 569 barangays across its component cities and municipalities, Barangay Alagao ranks 330th by 2020 population. Bulacan is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Alagao 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.