Barangay Mahilum

Barangay Mahilum forms part of Calatrava, a municipality in Negros Occidental, and is classified as a small barangay.

According to the 2020 Philippine census, Barangay Mahilum had a population of 1,094. This made it the 34th largest of 40 barangays in Calatrava by population, placing it among the smaller barangays of the municipality. Residents of Barangay Mahilum accounted for approximately 1.33% of the total population of Calatrava, which stood at 82,540 in the same census year.

The barangay recorded 1,134 residents in the 2015 intercensal count and 1,094 residents in the 2020 Census — a net change of -3.5%, consistent with a contracting settlement. Barangay Mahilum is officially classified as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Calatrava is a municipality comprising 40 barangays, and serves as the governing unit directly responsible for local services in Barangay Mahilum, including public health, sanitation, peace and order, and civil registration. Within the wider province of Negros Occidental, which contains 662 barangays across its component cities and municipalities, Barangay Mahilum ranks 543rd by 2020 population. Negros Occidental is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

Barangay Mahilum is governed by an elected Sangguniang Barangay composed of a Punong Barangay and seven kagawads, with the Sangguniang Kabataan representing the youth. The next BSKE, set for Monday, November 2, 2026, will elect officials to four-year terms as provided under Republic Act No. 12232.