Administrative divisions of Ilocos Sur
# Administrative divisions of Ilocos Sur

The province of Ilocos Sur is politically subdivided into 32 towns and 2

component cities, all of which are organized into two legislative districts. There are a total of 768 barangays in the province.

* † Provincial Capital and Component Cities
* ∗ Component Cities
* Towns

| City or Town | City or Town | District | Population (2010) | Population (2010) | Area | Area | Density | Density | Brgy. | Coordinates |
| - | - | - | - | - | - | - | - | - | - | - |
| | | | | | $km^2$ | sq mi | $/km^2$ | /sq mi | | |
| Alilem | Alilem | 2nd | 1.0% | 6,640 | 119.33 | 46.07 | 56 | 150 | 9 | 16°53′13″N 120°31′48″E﻿ / ﻿16.8870°N 120.5299°E﻿ / 16.8870; 120.5299﻿ (Alilem) |
| Banayoyo | Banayoyo | 2nd | 1.2% | 7,694 | 24.63 | 9.51 | 310 | 800 | 14 | 17°14′09″N 120°28′47″E﻿ / ﻿17.2358°N 120.4797°E﻿ / 17.2358; 120.4797﻿ (Banayoyo) |
| Bantay | Bantay | 1st | 5.2% | 34,323 | 76.60 | 29.58 | 450 | 1,200 | 34 | 17°34′54″N 120°23′11″E﻿ / ﻿17.5818°N 120.3865°E﻿ / 17.5818; 120.3865﻿ (Bantay) |
| Burgos | Burgos | 2nd | 1.8% | 11,679 | 44.38 | 17.14 | 260 | 670 | 26 | 17°18′58″N 120°30′33″E﻿ / ﻿17.3160°N 120.5093°E﻿ / 17.3160; 120.5093﻿ (Burgos) |
| Cabugao | Cabugao | 1st | 5.4% | 35,706 | 95.56 | 36.90 | 370 | 960 | 33 | 17°47′33″N 120°27′21″E﻿ / ﻿17.7926°N 120.4559°E﻿ / 17.7926; 120.4559﻿ (Cabugao) |
| Candon | ∗ | 2nd | 8.8% | 57,884 | 103.28 | 39.88 | 560 | 1,500 | 42 | 17°11′22″N 120°26′51″E﻿ / ﻿17.1895°N 120.4474°E﻿ / 17.1895; 120.4474﻿ (Candon) |
| Caoayan | Caoayan | 1st | 2.8% | 18,551 | 17.42 | 6.73 | 1,100 | 2,800 | 17 | 17°32′52″N 120°23′00″E﻿ / ﻿17.5477°N 120.3833°E﻿ / 17.5477; 120.3833﻿ (Caoayan) |
| Cervantes | Cervantes | 2nd | 2.5% | 16,573 | 234.70 | 90.62 | 71 | 180 | 13 | 16°59′24″N 120°44′07″E﻿ / ﻿16.9899°N 120.7354°E﻿ / 16.9899; 120.7354﻿ (Cervantes) |
| Galimuyod | Galimuyod | 2nd | 1.5% | 10,011 | 34.40 | 13.28 | 290 | 750 | 24 | 17°10′59″N 120°28′07″E﻿ / ﻿17.1830°N 120.4687°E﻿ / 17.1830; 120.4687﻿ (Galimuyod) |
| Gregorio del Pilar (Concepcion) | Gregorio del Pilar (Concepcion) | 2nd | 0.6% | 4,219 | 41.66 | 16.09 | 100 | 260 | 7 | 17°08′53″N 120°36′39″E﻿ / ﻿17.1481°N 120.6109°E﻿ / 17.1481; 120.6109﻿ (Gregorio del Pilar) |
| Lidlidda | Lidlidda | 2nd | 0.7% | 4,398 | 33.84 | 13.07 | 130 | 340 | 11 | 17°15′07″N 120°31′15″E﻿ / ﻿17.2519°N 120.5207°E﻿ / 17.2519; 120.5207﻿ (Lidlidda) |
| Magsingal | Magsingal | 1st | 4.3% | 28,302 | 84.98 | 32.81 | 330 | 850 | 30 | 17°41′06″N 120°25′33″E﻿ / ﻿17.6851°N 120.4257°E﻿ / 17.6851; 120.4257﻿ (Magsingal) |
| Nagbukel | Nagbukel | 2nd | 0.7% | 4,938 | 43.12 | 16.65 | 110 | 280 | 12 | 17°26′48″N 120°31′34″E﻿ / ﻿17.4466°N 120.5260°E﻿ / 17.4466; 120.5260﻿ (Nagbukel) |
| Narvacan | Narvacan | 2nd | 6.5% | 42,803 | 122.21 | 47.19 | 350 | 910 | 34 | 17°25′10″N 120°28′37″E﻿ / ﻿17.4194°N 120.4769°E﻿ / 17.4194; 120.4769﻿ (Narvacan) |
| Quirino (Angkaki) | Quirino (Angkaki) | 2nd | 1.3% | 8,535 | 240.10 | 92.70 | 36 | 93 | 9 | 17°08′12″N 120°40′35″E﻿ / ﻿17.1367°N 120.6765°E﻿ / 17.1367; 120.6765﻿ (Quirino) |
| Salcedo (Baugen) | Salcedo (Baugen) | 2nd | 1.7% | 10,935 | 103.44 | 39.94 | 110 | 280 | 21 | 17°09′03″N 120°32′10″E﻿ / ﻿17.1507°N 120.5361°E﻿ / 17.1507; 120.5361﻿ (Salcedo) |
| San Emilio | San Emilio | 2nd | 1.1% | 7,427 | 141.44 | 54.61 | 53 | 140 | 8 | 17°14′19″N 120°34′44″E﻿ / ﻿17.2386°N 120.5789°E﻿ / 17.2386; 120.5789﻿ (San Emilio) |
| San Esteban | San Esteban | 2nd | 1.2% | 8,072 | 19.62 | 7.58 | 410 | 1,100 | 10 | 17°19′47″N 120°26′42″E﻿ / ﻿17.3297°N 120.4451°E﻿ / 17.3297; 120.4451﻿ (San Esteban) |
| San Ildefonso | San Ildefonso | 1st | 1.1% | 7,075 | 11.35 | 4.38 | 620 | 1,600 | 15 | 17°37′30″N 120°23′35″E﻿ / ﻿17.6249°N 120.3931°E﻿ / 17.6249; 120.3931﻿ (San Ildefonso) |
| San Juan (Lapog) | San Juan (Lapog) | 1st | 3.8% | 25,199 | 64.37 | 24.85 | 390 | 1,000 | 32 | 17°44′32″N 120°27′30″E﻿ / ﻿17.7422°N 120.4583°E﻿ / 17.7422; 120.4583﻿ (San Juan) |
| San Vicente | San Vicente | 1st | 1.8% | 11,720 | 12.60 | 4.86 | 930 | 2,400 | 7 | 17°35′39″N 120°22′22″E﻿ / ﻿17.5941°N 120.3729°E﻿ / 17.5941; 120.3729﻿ (San Vicente) |
| Santa | Santa | 2nd | 2.3% | 15,106 | 109.10 | 42.12 | 140 | 360 | 26 | 17°29′10″N 120°26′04″E﻿ / ﻿17.4860°N 120.4344°E﻿ / 17.4860; 120.4344﻿ (Santa) |
| Santa Catalina | Santa Catalina | 1st | 2.1% | 13,597 | 9.68 | 3.74 | 1,400 | 3,600 | 9 | 17°35′20″N 120°21′48″E﻿ / ﻿17.5888°N 120.3634°E﻿ / 17.5888; 120.3634﻿ (Santa Catalina) |
| Santa Cruz | Santa Cruz | 2nd | 5.8% | 37,911 | 88.78 | 34.28 | 430 | 1,100 | 49 | 17°05′04″N 120°27′07″E﻿ / ﻿17.0844°N 120.4520°E﻿ / 17.0844; 120.4520﻿ (Santa Cruz) |
| Santa Lucia | Santa Lucia | 2nd | 3.8% | 24,981 | 49.72 | 19.20 | 500 | 1,300 | 36 | 17°07′02″N 120°26′53″E﻿ / ﻿17.1173°N 120.4480°E﻿ / 17.1173; 120.4480﻿ (Santa Lucia) |
| Santa Maria | Santa Maria | 2nd | 4.3% | 28,597 | 63.31 | 24.44 | 450 | 1,200 | 33 | 17°22′03″N 120°28′51″E﻿ / ﻿17.3676°N 120.4807°E﻿ / 17.3676; 120.4807﻿ (Santa Maria) |
| Santiago | Santiago | 2nd | 2.7% | 17,958 | 46.36 | 17.90 | 390 | 1,000 | 24 | 17°17′38″N 120°26′43″E﻿ / ﻿17.2940°N 120.4453°E﻿ / 17.2940; 120.4453﻿ (Santiago) |
| Santo Domingo | Santo Domingo | 1st | 4.2% | 27,596 | 55.49 | 21.42 | 500 | 1,300 | 36 | 17°38′16″N 120°24′36″E﻿ / ﻿17.6378°N 120.4101°E﻿ / 17.6378; 120.4101﻿ (Santo Domingo) |
| Sigay | Sigay | 2nd | 0.4% | 2,419 | 81.55 | 31.49 | 30 | 78 | 7 | 17°02′34″N 120°34′46″E﻿ / ﻿17.0429°N 120.5795°E﻿ / 17.0429; 120.5795﻿ (Sigay) |
| Sinait | Sinait | 1st | 3.9% | 25,427 | 65.56 | 25.31 | 390 | 1,000 | 44 | 17°51′59″N 120°27′22″E﻿ / ﻿17.8664°N 120.4561°E﻿ / 17.8664; 120.4561﻿ (Sinait) |
| Sugpon | Sugpon | 2nd | 0.6% | 3,820 | 57.11 | 22.05 | 67 | 170 | 6 | 16°49′38″N 120°29′45″E﻿ / ﻿16.8272°N 120.4959°E﻿ / 16.8272; 120.4959﻿ (Sugpon) |
| Suyo | Suyo | 2nd | 1.6% | 10,622 | 124.00 | 47.88 | 86 | 220 | 8 | 16°58′33″N 120°31′30″E﻿ / ﻿16.9758°N 120.5249°E﻿ / 16.9758; 120.5249﻿ (Suyo) |
| Tagudin | Tagudin | 2nd | 5.8% | 38,122 | 151.19 | 58.37 | 250 | 650 | 43 | 16°56′04″N 120°26′42″E﻿ / ﻿16.9345°N 120.4450°E﻿ / 16.9345; 120.4450﻿ (Tagudin) |
| Vigan | † | 1st | 7.6% | 49,747 | 25.12 | 9.70 | 2,000 | 5,200 | 39 | 17°34′22″N 120°23′12″E﻿ / ﻿17.5729°N 120.3867°E﻿ / 17.5729; 120.3867﻿ (Vigan) |
| Total | Total | Total | Total | 658,587 | 2,596.00 | 1,002.32 | 250 | 650 | 768 | (see GeoGroup box) |
| $^^$ Former names are $italicized.^^$ Coordinates mark the city/town center, and are sortable by latitude. |||||||||||
