Barangay Santisima Trinidad

Barangay Santisima Trinidad forms part of City of Malolos, a city in Bulacan, and is classified as a large barangay.

According to the 2020 Philippine census, Barangay Santisima Trinidad had a population of 6,688. This made it the 14th largest of 51 barangays in City of Malolos by population, placing it in the upper half of the city. Residents of Barangay Santisima Trinidad accounted for approximately 2.56% of the total population of City of Malolos, which stood at 261,189 in the same census year.

The barangay recorded 6,524 residents in the 2015 intercensal count and 6,688 residents in the 2020 Census — a net change of +2.5%, consistent with a growing settlement. Barangay Santisima Trinidad is officially classified as urban, reflecting the density and built-up character of the area.

City of Malolos is a city comprising 51 barangays, and serves as the governing unit directly responsible for local services in Barangay Santisima Trinidad, including public health, sanitation, peace and order, and civil registration. Within the wider province of Bulacan, which contains 569 barangays across its component cities and municipalities, Barangay Santisima Trinidad ranks 169th by 2020 population. Bulacan 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 Santisima Trinidad 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.