Barangay San Isidro West

Barangay San Isidro West forms part of Santa Maria, a municipality in Isabela, and is classified as a small barangay.

According to the 2020 Philippine census, Barangay San Isidro West had a population of 1,035. This made it the 12th largest of 20 barangays in Santa Maria by population, placing it in the middle tier of the municipality. Residents of Barangay San Isidro West accounted for approximately 4.02% of the total population of Santa Maria, which stood at 25,758 in the same census year.

Census comparisons between 2015 and 2020 show Barangay San Isidro West moving from 1,072 residents to 1,035 residents, an intercensal change of -3.5%. The trajectory indicates a contracting community. Barangay San Isidro West is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Santa Maria is a municipality comprising 20 barangays, and serves as the governing unit directly responsible for local services in Barangay San Isidro West, including public health, sanitation, peace and order, and civil registration. Within the wider province of Isabela, which contains 1,055 barangays across its component cities and municipalities, Barangay San Isidro West ranks 637th by 2020 population. Isabela 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 San Isidro West 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.