Ilocos Sur's 3rd congressional district

Ilocos Sur's 3rd congressional district was one of the three congressional districts of the Philippines in the province of Ilocos Sur in existence between 1907 and 1919. It was created in 1907 from former territories of the province under Philippine Commission Act No. 1582 following the passage of the 1902 Philippine Organic Act. The district was originally composed of the municipalities of Bangued, Bucay, Dolores, La Paz, Pilar, San Quintin and Santa, most of which were located in Abra, a sub-province of Ilocos Sur since 1905. It was a single-member district throughout the three legislatures of the Philippine Assembly from 1907 to 1916 and the first legislature of the House of Representatives from 1916 to 1919.

The district was represented by a total of only three representatives throughout its brief existence. It was abolished in 1919 following the passage of Legislative Act No. 2683 which created the province of Abra in 1917. As a result, Santa remained in Ilocos Sur and was redistricted to the 2nd district, while the other towns became part of Abra and were redistricted to its new at-large district. The district was last represented by Eustaquio Purugganan of the Nacionalista Party (NP) who was also elected as the first representative of Abra's at-large congressional district following its dissolution.

Representation history
{| class=wikitable ! rowspan="2" | # ! rowspan="2" colspan=2 | Member ! colspan=2 | Term of office ! rowspan="2" | Legislature ! rowspan="2" | Party ! rowspan="2" | Electoral history ! rowspan="2" | Constituent LGUs !Start!!End
 * colspan="9" style="text-align:center;" |
 * colspan="9" style="text-align:center;" |

Ilocos Sur's 3rd district for the Philippine Assembly

 * colspan="9" style="text-align:center;" | District created January 9, 1907.
 * rowspan="2" style="text-align:center;" | 1
 * rowspan="2" style="background:;" |
 * rowspan="2" | Juan Villamor
 * rowspan="2" | October 16, 1907
 * rowspan="2" | October 16, 1912
 * style="text-align:center;" | 1st
 * rowspan="2" | Nacionalista
 * Elected in 1907.
 * rowspan="2" style="text-align:center;" | 1907–1912 Bangued, Bucay, Dolores, La Paz, Pilar, San Quintin, Santa
 * style="text-align:center;" | 2nd
 * Re-elected in 1909.
 * style="text-align:center;" | 2
 * style="background:;" |
 * Julio Borbón
 * October 16, 1912
 * October 16, 1916
 * style="text-align:center;" | 3rd
 * Nacionalista
 * Elected in 1912.
 * style="text-align:center;" | 1912–1916 Bangued, Bucay, Dolores, La Paz, Pilar, San Quintin, Santa, Tayum
 * colspan="9" style="text-align:center;" |
 * Nacionalista
 * Elected in 1912.
 * style="text-align:center;" | 1912–1916 Bangued, Bucay, Dolores, La Paz, Pilar, San Quintin, Santa, Tayum
 * colspan="9" style="text-align:center;" |
 * colspan="9" style="text-align:center;" |

Ilocos Sur's 3rd district for the House of Representatives of the Philippine Islands

 * style="text-align:center;" | 3
 * style="background:;" |
 * Eustaquio Purugganan
 * October 16, 1916
 * June 3, 1919
 * style="text-align:center;" | 4th
 * Nacionalista
 * Elected in 1916. Redistricted to Abra's at-large district.
 * style="text-align:center;" | 1916–1919 Bangued, Bucay, Dolores, La Paz, Pilar, San Quintin, Santa, Tayum
 * colspan="9" style="text-align:center;" | District dissolved into Abra's at-large district and Ilocos Sur's 2nd district.
 * }
 * colspan="9" style="text-align:center;" | District dissolved into Abra's at-large district and Ilocos Sur's 2nd district.
 * }