Ilocos Sur

Ilocos Sur
Clockwise from the top: Santa Maria Basilica Shrine, Vigan City, Bantay Church, Mount Tuwato, Bantay Church Belltower
Nickname: 
The Heritage Haven of the North
Location in the Philippines
Interactive map of Ilocos Sur
Coordinates: 17°20′N 120°35′E / 17.33°N 120.58°E / 17.33; 120.58
CountryPhilippines
RegionIlocos Region
FoundedFebruary 2, 1818
CapitalVigan
Largest cityCandon
Government
 • GovernorJeremias C. Singson (NPC/Bileg)
 • Vice GovernorRyan Luis V. Singson (Lakas/Bileg)
 • LegislatureIlocos Sur Provincial Board
Area
 • Total
2,596.00 km2 (1,002.32 sq mi)
 • Rank51st out of 82
Highest elevation
(Mount Camingingel)
2,371 m (7,779 ft)
Population
 (2024 census)
 • Total
709,991
 • Rank43rd out of 82
 • Density273.494/km2 (708.347/sq mi)
  • Rank33rd out of 82
Demonyms
  • Ilocano (m/n)
  • Ilocana (f)
Divisions
 • Independent cities0
 • Component cities
 • Municipalities
 • Barangays768
 • DistrictsLegislative districts of Ilocos Sur
Time zoneUTC+8 (PST)
ISO 3166 codePH-ILS
Spoken languages
HDI 0.70 (High)
HDI rank19th (2019)
Websitemis.ilocossur.gov.ph

Ilocos Sur (lit.'South Ilocos'), officially the Province of Ilocos Sur (Ilocano: Probinsia ti Ilocos Sur; Tagalog: Lalawigan ng Ilocos Sur), is a province in the Philippines located in the Ilocos Region in Luzon. Located on the mouth of the Mestizo River is the capital of Vigan, while Candon is the most-populous city. Ilocos Sur is bordered by Ilocos Norte and Abra to the north, Mountain Province to the east, La Union and Benguet to the south and the South China Sea to the west.

Ilocos Sur was established in 1818 when the province of Ilocos was split into two: the north (now Ilocos Norte) and the south (Ilocos Sur). At that time, it included parts of Abra and the upper half of present-day La Unión. The current boundaries of the province set in March 1917 by virtue of Act No. 2683.

The province is home to two UNESCO World Heritage Sites, namely, the Heritage City of Vigan and the Santa Maria Basilica Shrine.