Barangay San Ildefonso (Pob.)

Situated in San Nicolas, Ilocos Norte, Barangay San Ildefonso (Pob.) is one of 24 barangays that make up the municipality within Ilocos Region.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay San Ildefonso (Pob.) had a population of 1,743. This made it the 11th largest of 24 barangays in San Nicolas by population, placing it in the middle tier of the municipality. Residents of Barangay San Ildefonso (Pob.) accounted for approximately 4.48% of the total population of San Nicolas, which stood at 38,895 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay San Ildefonso (Pob.) changed from 1,470 to 1,743, a shift of +18.6% over the five-year period. This places the barangay among those with growing populations in San Nicolas. The Philippine Statistics Authority classifies Barangay San Ildefonso (Pob.) as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

San Nicolas is a municipality comprising 24 barangays, and serves as the governing unit directly responsible for local services in Barangay San Ildefonso (Pob.), including public health, sanitation, peace and order, and civil registration. Within the wider province of Ilocos Norte, which contains 559 barangays across its component cities and municipalities, Barangay San Ildefonso (Pob.) ranks 66th by 2020 population. Ilocos Norte is classified as a 1st 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.