Barangay Guitnang Bayan I (Pob.)

Barangay Guitnang Bayan I (Pob.) forms part of San Mateo, a municipality in Rizal, and is classified as a very large barangay.

According to the 2020 Philippine census, Barangay Guitnang Bayan I (Pob.) had a population of 35,121. This made it the 2nd largest of 15 barangays in San Mateo by population, placing it among the most populous barangays of the municipality. Residents of Barangay Guitnang Bayan I (Pob.) accounted for approximately 12.85% of the total population of San Mateo, which stood at 273,306 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Guitnang Bayan I (Pob.) changed from 30,598 to 35,121, a shift of +14.8% over the five-year period. This places the barangay among those with growing populations in San Mateo. Barangay Guitnang Bayan I (Pob.) is officially classified as urban, reflecting the density and built-up character of the area.

San Mateo is a municipality comprising 15 barangays, and serves as the governing unit directly responsible for local services in Barangay Guitnang Bayan I (Pob.), including public health, sanitation, peace and order, and civil registration. Within the wider province of Rizal, which contains 189 barangays across its component cities and municipalities, Barangay Guitnang Bayan I (Pob.) ranks 27th by 2020 population. Rizal is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Like every Philippine barangay, Barangay Guitnang Bayan I (Pob.) 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.