古斯尔（英语：gusle 或 gusla，保加利亚语：Гусла，克罗地亚语：Gusle，塞尔维亚语：Гусле），又译作古斯里或古斯勒，是一种流传于巴尔干半岛地区的弓弦乐器，它多半搭配演奏者的歌声来演唱，是东欧地区民间的一种说唱艺术，乐器大多为一根弦，少数地区使用两根弦，弓弦由马尾制作，演奏时放在两腿间演奏。

The gusle (Serbo-Croatian:gusle (Serbian Cyrillic:гусле), Albanian:lahuta, Bulgarian:гусла) is a single-stringed musical instrument (and musical style) traditionally used in the Dinarides region of the Southeastern Europe.

The instrument is always accompanied by singing; musical folklore, specifically epic poetry. The gusle player (guslar or "lahutar" in Albanian) holds the instrument vertically between his knees, with the left hand fingers on the strings. The strings are never pressed to the neck, giving a harmonic and unique sound.