| Ilūkste | |
| Settlement Type: | Town |
| Subdivision Type: | Country |
| Subdivision Name: |  Latvia |
| Subdivision Type1: | Municipality |
| Subdivision Name1: | Augšdaugava Municipality |
| Established Title: | Town rights |
| Established Date: | 1917 |
| Pushpin Map: | Latvia |
| Pushpin Label Position: | above |
| Pushpin Mapsize: | 300 |
| Pushpin Map Caption: | Location in Latvia |
| Coordinates: | 55.9667°N 43°W |
| Leader Title: | Mayor |
| Leader Name: | Stefans Rāzna |
| Blank Name Sec1: | Number of city council members |
| Blank Info Sec1: | 11 |
| Elevation M: | 100 |
| Population Density Km2: | auto |
| Postal Code Type: | Postal code |
| Postal Code: | LV-5447 |
| Area Code Type: | Calling code |
| Area Code: | +371 654 |
| Timezone1: | EET |
| Utc Offset1: | +2 |
| Timezone1 Dst: | EEST |
| Utc Offset1 Dst: | +3 |
Ilūkste (; Lithuanian: Alūksta, Ilūkšta; German: Illuxt) is a town in Augšdaugava Municipality in the Selonia region of Latvia. The population in 2020 was 2,216.[1]
The territory of modern Ilūkste was inhabited by the Selonians, an ancient Baltic tribe. As a settlement Ilūkste started to grow in the beginning of the 16th century when it was part of the Livonian Confederation and was administered by the Komtur of Daugavpils. Ilūkste was first mentioned in written sources in 1559 as a small village, part of the estate lands of Count Kasper Sieberg.After the secularization of the Livonian Order, Ilūkste became part of the Duchy of Courland and Semigallia. In 1567 a Lutheran church was built in Ilūkste. Many Russian Old Believers found refuge in Ilūkste during this period.During 17th century local landowner Bartholomew Zieberg offered refugee to Jesuits who were expelled from Swedish-controlled Riga. As a result, a wooden Catholic church was built in Ilūkste in 1690. In the 18th century Jesuits constructed a large Catholic church with two towers which at that time was one of the biggest in Latvia.
After the Duchy of Courland was incorporated in the Russian Empire in 1795, thanks to its strategic location at the crossroads of Lithuania, Belarus and Daugavpils, Ilūkste became an important trade city and regional center.In 1816 a Uniate church was built in Ilūkste. In the 19th century many Jewish merchants settled in Ilūkste and annual fairs were held. In 1840 a highway from St. Petersburg to Warsaw was constructed nearby which stimulated further development. In 1865 a new Lutheran church was built. In 1873 the Daugavpils-Tilsit railway line was constructed through the town.In 1910 a Russian teacher institute was opened in Ilūkste.
In World War I, Ilūkste was situated on the fighting front line, and by the war's end the city was totally destroyed. There were no intact houses left in Ilūkste and also all churches were damaged. Ilūkste was granted town rights in 1917 however it never fully regained its pre-war level of prosperity. In 1927 a new school building was constructed in town and Latvian poet, playwright and at that moment Minister of Education Rainis participated in the opening ceremony.
During the Soviet period, some industries shifted from Daugavpils to Ilūkste.