San Manuel (formerly Callang), officially the Municipality of San Manuel (; ), is a municipality in the province of Isabela, Philippines. According to the , it has a population of people.
In 1957, the barrios of Callang, Eden, Babanuang, Cabaritan, Santa Cruz, Malalinta, Mararigue, Calaocan, and Caraniogan of Roxas were separated to form Callang. In 1965, the town was renamed as San Manuel by virtue of Republic Act No. 4600.
San Manuel is situated from the provincial capital Ilagan, and from the country's capital city of Manila.
San Manuel is politically subdivided into 19 barangays. Each barangay consists of puroks while some have sitios.
In the 2024 census, the population of San Manuel was 34,740 people, with a density of .
The town's primary economic activity is farming.
As a municipality in the Province of Isabela, government officials at the provincial and municipal levels are voted by the town. The provincial government has political jurisdiction over most local transactions of the municipal government.
The Municipality of San Manuel is governed by a mayor, designated as its local chief executive, 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 through polls held every three years.
Barangays are also headed by elected officials: Barangay Captain, Barangay Council, whose members are called Barangay Councilors. The barangays have SK federation which represents the barangay, headed by SK chairperson and whose members are called SK councilors. All officials are also elected every three years.
San Manuel, belonging to the fifth legislative district of the province of Isabela, currently represented by Hon. Faustino Michael Carlos T. Dy III.
The Schools Division of Isabela governs the town's public education system. The division office is a field office of the DepEd in Cagayan Valley region. The San Manuel Schools District Office governs all public and private elementary and high schools throughout the municipality.