Barangay San Mateo

Classified as a small barangay, Barangay San Mateo is one of the administrative divisions of City of Borongan in Eastern Samar, Eastern Visayas, Philippines.

According to the 2020 Philippine census, Barangay San Mateo had a population of 1,462. This made it the 18th largest of 61 barangays in City of Borongan by population, placing it in the upper half of the city. Residents of Barangay San Mateo accounted for approximately 2.03% of the total population of City of Borongan, which stood at 71,961 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay San Mateo changed from 1,571 to 1,462, a shift of -6.9% over the five-year period. This places the barangay among those with contracting populations in City of Borongan. Barangay San Mateo is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

City of Borongan is a city comprising 61 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 79th 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.

Like every Philippine barangay, Barangay San Mateo is led by an elected Punong Barangay (barangay captain) supported by seven Sangguniang Barangay members (kagawads), an SK Chairperson, a Barangay Secretary, and a Barangay Treasurer. The next Barangay and Sangguniang Kabataan Elections (BSKE) are scheduled for Monday, November 2, 2026, with officials serving four-year terms under Republic Act No. 12232.