Barangay Union

Barangay Union forms part of City of Cauayan, a city in Isabela, and is classified as a small barangay.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Union had a population of 1,549. This made it the 33rd largest of 65 barangays in City of Cauayan by population, placing it in the middle tier of the city. Residents of Barangay Union accounted for approximately 1.08% of the total population of City of Cauayan, which stood at 143,403 in the same census year.

The barangay recorded 1,407 residents in the 2015 intercensal count and 1,549 residents in the 2020 Census — a net change of +10.1%, consistent with a growing settlement. The Philippine Statistics Authority classifies Barangay Union as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

City of Cauayan is a city comprising 65 barangays, and serves as the governing unit directly responsible for local services in Barangay Union, 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 Union ranks 406th 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 Union 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.