San Juan, officially the Municipality of San Juan (; ), formerly called as Lapog, is a municipality in the province of Ilocos Sur, Philippines. According to the , it has a population of people.
The town produces the most number of goods made of buri leaf in the province. it is recognized sometimes as the "Buri Capital of Ilocos Sur".
The town was named in honor of its patron, St. John the Baptist.
The town was established in 1772 as Lapog. Over the years, the name of the municipality went through a series of changes. The early settlers and occupants called it "Lapo", short for "Lapo-Lapo", a tall grass which grew everywhere in the area. In 1772, Don Tomas Aquino, the first local leader, initiated the organization of the scattered communities into one, calling the place "Lapog", a derivative of local vernacular "Lap-Lapog" which means unirrigated land.
It was stricken by all sorts of plagues and epidemics (like the smallpox epidemics of 1808 and 1918âÂÂ19, locust infestation in 1903, and destruction of ricefields by worms called "arabas" in 1905). Bessang Pass, just south of the poblacion, was constructed in 1874. Americans destroyed their town hall in 1903. But despite these misfortunes, San Juan progressed into a prosperous community.
For 189 years, "Lapog" remained in the records as the official name of the town until June 18, 1961, when Republic Act No. 3386 was enacted to rename the town, "San Juan". Since most of the inhabitants were of the belief that religious names bring peace, happiness, and prosperity, the town was renamed "San Juan", after the name of its patron saint, Saint John the Baptist.
The Municipality of San Juan is bordered by Cabugao to the north, Magsingal to the south, the provinces of Ilocos Norte and Abra to the east.
San Juan is situated from the provincial capital Vigan, and from the country's capital city of Manila.
San Juan is politically subdivided into 32 barangays. Each barangay consists of puroks and some have sitios.
In the 2024 census, San Juan had a population of 26,709 people. The population density was .
San Juan, belonging to the first congressional district of the province of Ilocos Sur, 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.
The San Juan Schools District Office governs all educational institution within the municipality.