Barangay Ilayang Ilog B

Situated in Lopez, Quezon, Barangay Ilayang Ilog B is one of 95 barangays that make up the municipality within CALABARZON.

According to the 2020 Census of Population and Housing conducted by the Philippine Statistics Authority, Barangay Ilayang Ilog B had a population of 231. This made it the 88th largest of 95 barangays in Lopez by population, placing it among the smaller barangays of the municipality. Residents of Barangay Ilayang Ilog B accounted for approximately 0.24% of the total population of Lopez, which stood at 94,657 in the same census year.

Between the 2015 and 2020 censuses, the population of Barangay Ilayang Ilog B changed from 271 to 231, a shift of -14.8% over the five-year period. This places the barangay among those with contracting populations in Lopez. The Philippine Statistics Authority classifies Barangay Ilayang Ilog B as rural, a designation applied to barangays with lower population density and predominantly non-built-up land use.

Lopez is a municipality comprising 95 barangays, and serves as the governing unit directly responsible for local services in Barangay Ilayang Ilog B, including public health, sanitation, peace and order, and civil registration. Within the wider province of Quezon, which contains 1,242 barangays across its component cities and municipalities, Barangay Ilayang Ilog B ranks 1158th by 2020 population. Quezon is classified as a 1st by the Bureau of Local Government Finance, a category that reflects the province's annual regular income.

The barangay's legislative and executive affairs are handled by a Punong Barangay and the Sangguniang Barangay, elected nationwide during the Barangay and SK Elections. The next BSKE is scheduled for Monday, November 2, 2026, following the synchronized election schedule set by COMELEC Resolution No. 11191.