Barangay Sinai

Barangay Sinai forms part of Sergio osmeña Sr., a municipality in Zamboanga Del Norte, and is classified as a small barangay.

According to the 2020 Philippine census, Barangay Sinai had a population of 1,003. This made it the 11th largest of 39 barangays in Sergio osmeña Sr. by population, placing it in the upper half of the municipality. Residents of Barangay Sinai accounted for approximately 3.14% of the total population of Sergio osmeña Sr., which stood at 31,942 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Sinai changed from 1,005 to 1,003, a shift of -0.2% over the five-year period. This places the barangay among those with broadly stable populations in Sergio osmeña Sr.. Barangay Sinai is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Sergio osmeña Sr. is a municipality comprising 39 barangays, and serves as the governing unit directly responsible for local services in Barangay Sinai, including public health, sanitation, peace and order, and civil registration. Within the wider province of Zamboanga Del Norte, which contains 691 barangays across its component cities and municipalities, Barangay Sinai ranks 392nd by 2020 population. Zamboanga Del Norte is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Sinai 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.