Peñablanca, officially the Municipality of Peñablanca (; ; ), is a municipality in the province of Cagayan, Philippines. According to the , it has a population of people.
Peñablanca is home to the charcoal-drawn Peñablanca petrographs and the Callao Limeston Formation. Both the Peñablanca Petrographs and the Callao Limestone Formation are included as tentative sites of the Philippines for future inclusion in the UNESCO World Heritage List. The Callao Limestone Formation has at least 93 archaeological sites that yielded stone tools of Paleolithic industry and bones and shells of animals still living in the vicinity.
Named after its prominent white rock formations, Peñablanca was formerly a barrio of Tuguegarao named Bubug. However, it also went by other names such as Alimannao, which was said to have been derived from a German rancher named Otto Weber, who, when one of his servants was asked who owned the cows in the area, responded in Itawis: cua na Aliman yao (they belong to the German). Another name for the place was camasi, from the native word for tomato, which abounded in the area. Both Alimannao and Camasi are now names of barrios in the municipality.
Peñablanca was made a separate municipality by the Spaniards on November 20, 1886. Its first inhabitants were Kalingas (unbaptized Irrayas) and Negritos.
The municipality is home to the Peñablanca Protected Landscape and Seascape which contains the Callao Cave (part of the Callao Limestone Formation Paleolithic Archaeological Site), one of the province's well-known landmarks and tourist spots.
Peñablanca is situated from of the provincial capital Tuguegarao, and north of the country's capital city of Manila.
Peñablanca is divided into 24 barangays. Each barangay consists of puroks while some have sitios.
In the 2024 census, the population of Peñablanca was 50,856 people, with a density of .
Peñablanca is part of the third legislative district of the province of Cagayan. It is governed by a mayor, designated as its local chief executive<sub>,</sub> and by a municipal council as its legislative body in accordance with the Local Government Code. The mayor, vice mayor, and the municipal councilors are elected directly by the people through an election held every three years.
The Schools Division of Cagayan governs the town's public education system. The division office is a field office of the DepEd in Cagayan Valley region. There are two schools district offices which govern the public and private elementary and high schools throughout the municipality. These are Peñablanca East District, and Peñablanca West District.