Supraśl ([ˈsupraɕl]; Belarusian: Су́прасль; Lithuanian: Supraslė) is a town and former episcopal see in Białystok County, in Podlaskie Voivodeship, in north-eastern Poland.

In 1823, a 10th-century manuscript, the oldest Slavic literary work in Poland, named the Codex Suprasliensis, was discovered in the Supraśl Monastery by Michał Bobrowski.

In 1834 manufacturer Wilhelm Fryderyk Zachert came from Zgierz to Supraśl and significantly contributed to the development of the village into a town.

It is the home of the Supraśl Lavra, founded by Aleksander Chodkiewicz, one of six Eastern Orthodox monasteries for men in Poland.

Other historic landmarks include the Buchholtz Palace, which now houses the Art High School, the Catholic churches of Our Lady Queen of Poland and of the Holy Trinity, the town hall, cinema, a 19th-century park and historic wooden architecture.