Barangay Lower Santo Niño

Classified as a small barangay, Barangay Lower Santo Niño is one of the administrative divisions of Mahayag in Zamboanga Del Sur, Zamboanga Peninsula, Philippines.

According to the 2020 Philippine census, Barangay Lower Santo Niño had a population of 1,404. This made it the 15th largest of 29 barangays in Mahayag by population, placing it in the middle tier of the municipality. Residents of Barangay Lower Santo Niño accounted for approximately 2.91% of the total population of Mahayag, which stood at 48,258 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Lower Santo Niño changed from 1,451 to 1,404, a shift of -3.2% over the five-year period. This places the barangay among those with contracting populations in Mahayag. Barangay Lower Santo Niño is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Mahayag is a municipality comprising 29 barangays, and serves as the governing unit directly responsible for local services in Barangay Lower Santo Niño, including public health, sanitation, peace and order, and civil registration. Within the wider province of Zamboanga Del Sur, which contains 779 barangays across its component cities and municipalities, Barangay Lower Santo Niño ranks 237th by 2020 population. Zamboanga Del Sur 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.