San Guillermo
Municipality
Municipality of San Guillermo
Flag Seal
Map of Isabela with San Guillermo highlighted
OpenStreetMap
San Guillermo Location within the Philippines
Coordinates: 16°43′28″N 121°48′36″E / 16.7244°N 121.81°E / 16.7244; 121.81
Country	Philippines
Region	Cagayan Valley
Province	Isabela
District	6th district
Founded	June 17, 1967
Named for	Eugenio Guillermo
Barangays	26 (see Barangays)
Government  [1]
• Type	Sangguniang Bayan
• Mayor	Felipe N. Guyud, Jr.
• Vice Mayor	Bernadine M. Lucas
• Representative	Faustino A. Dy V
• Electorate	13,719 voters (2022)
Area [2]
• Total	325.49 km2 (125.67 sq mi)
Elevation	88 m (289 ft)
Highest elevation	128 m (420 ft)
Lowest elevation	43 m (141 ft)
Population  (2020 census)[3]
• Total	20,915
• Density	64/km2 (170/sq mi)
• Households	4,989
Economy
• Income class	4th municipal income class
• Poverty incidence	22.09 % (2021)[4]
• Revenue	₱ 141.3 million (2020)
• Assets	₱ 352 million (2020)
• Expenditure	₱ 104.4 million (2020)
• Liabilities	₱ 77.05 million (2020)
Service provider
• Electricity	Isabela 1 Electric Cooperative (ISELCO 1)
Time zone	UTC+8 (PST)
ZIP code	3308
PSGC	023128000
IDD : area code	+63 (0)78
Native languages	Ilocano Tagalog
Website	www.sanguillermo-isabela.gov.ph

San Guillermo (Spanish for Saint William), officially the Municipality of San Guillermo, is a municipality in the province of Isabela, Philippines. According to the 2020 census, it has a population of 20,915 people.^[3]

The town was named after Eugenio Guillermo, former mayor of Angadanan.

On June 17, 1967, the municipality of San Guillermo was created by virtue of Republic Act No. 4906,^[5] sponsored by Melanio Singson, the then-representative of Isabela's lone district. It took 15 barangays from Angadanan (i.e. Anonang, Colorado, Calaoagan, Dipacamo, Peredo Edcor, Guam, Nakar, Palawan, Progreso, San Francisco Norte, San Mariano Norte, San Mariano Sur, Villa Rose, Villa Sanchez, and Villa Teresita) and four from Echague (i.e. Aringay, Dingading, San Francisco Sur and Sinalugan).

Due to a noticeable increase in the rate of population migration and potential economic growth, additional barangays were created during the term of Mayor Alvaro Filart, such as barangays Burgos, Dietban, Estrella, Rizal, San Rafael and Villa Remedios. Subsequently, barangay Peredo Edcor was split into two barangays, namely: Centro 1 and Centro 2, which is now the poblacion and the municipality's official seat.^[6]

San Guillermo is politically subdivided into 26 barangays. ^[7] Each barangay consists of puroks while some have sitios.

In the 2020 census, the population of San Guillermo, Isabela, was 20,915 people,^[3] with a density of 64 inhabitants per square kilometre or 170 inhabitants per square mile.

Poverty incidence of San Guillermo

As a municipality in the Province of Isabela, government officials in the provincial level are voted by the electorates of the town. The provincial government have political jurisdiction over local transactions of the municipal government.

The municipality of San Guillermo 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 councilors are elected directly by the people through an election which is being 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 Guillermo, belonging to the sixth legislative district of the province of Isabela, currently represented by Hon. Faustino A. Dy V.^[22]

The Schools Division of Isabela governs the town's public education system.^[23] The division office is a field office of the DepEd in Cagayan Valley region.^[24] The office governs the public and private elementary and public and private high schools throughout the municipality.

• Municipal Profile at the National Competitiveness Council of the Philippines
• San Guillermo at the Isabela Government Website
• Local Governance Performance Management System
• Philippine Standard Geographic Code
• Philippine Census Information
• Municipality of San Guillermo