Barangay San Diego

Barangay San Diego is a large barangay in the municipality of Lian, located in the province of Batangas, in the CALABARZON region of the Philippines.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay San Diego had a population of 5,181. This made it the 2nd largest of 19 barangays in Lian by population, placing it among the most populous barangays of the municipality. Residents of Barangay San Diego accounted for approximately 9.21% of the total population of Lian, which stood at 56,280 in the same census year.

Census comparisons between 2015 and 2020 show Barangay San Diego moving from 4,483 residents to 5,181 residents, an intercensal change of +15.6%. The trajectory indicates a growing community. The Philippine Statistics Authority classifies Barangay San Diego as urban, reflecting the density and built-up character of the area.

Lian is a municipality comprising 19 barangays, and serves as the governing unit directly responsible for local services in Barangay San Diego, including public health, sanitation, peace and order, and civil registration. Within the wider province of Batangas, which contains 1,078 barangays across its component cities and municipalities, Barangay San Diego ranks 110th by 2020 population. Batangas is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay San Diego 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.