San Esteban, officially the Municipality of San Esteban (; ), is a municipality in the province of Ilocos Sur, Philippines. According to the , it has a population of people.
The Spaniards named the pueblo (the equivalent of a municipality in present-day terms) San Esteban (formerly known as Cabagbagototan) purportedly in relation to reports they received about a vagabond named Iban having been stoned to death and beheaded by hostile natives in the place called "Naglawlawayan," which is an early place of worship by the natives and currently the site of the municipal cemetery. "Iban" is the Ilocano equivalent of "Stephen," hence the pueblo being named San Esteban.
San Esteban was founded by Augustinian friars in 1625, but was always attached to Nueva Coveta (present-day Burgos) and the municipality of Santiago until 1911. It was once a visita of Narvacan because of a shortage of ministers.
San Esteban is situated from the provincial capital Vigan, and from the country's capital city of Manila.
San Esteban is politically subdivided into 10 barangays. Each barangay consists of puroks and some have sitios.
In the 2024 census, San Esteban had a population of 8,621 people. The population density was .
San Estaban, belonging to the second 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 Buros-San Esteban Schools District Office governs all schools within the municipality of San Esteban. Also oversees all schools located in Burgos.