Barangay San Mateo

Barangay San Mateo forms part of Sulat, a municipality in Eastern Samar, and is classified as a very small barangay.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay San Mateo had a population of 456. This made it the 14th largest of 18 barangays in Sulat by population, placing it among the smaller barangays of the municipality. Residents of Barangay San Mateo accounted for approximately 2.89% of the total population of Sulat, which stood at 15,758 in the same census year.

Census comparisons between 2015 and 2020 show Barangay San Mateo moving from 397 residents to 456 residents, an intercensal change of +14.9%. The trajectory indicates a growing community. The Philippine Statistics Authority classifies Barangay San Mateo as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Sulat is a municipality comprising 18 barangays, and serves as the governing unit directly responsible for local services in Barangay San Mateo, including public health, sanitation, peace and order, and civil registration. Within the wider province of Eastern Samar, which contains 597 barangays across its component cities and municipalities, Barangay San Mateo ranks 381st by 2020 population. Eastern Samar is classified as a 2nd 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.