The gusle (Albanian: lahuta, Croatian: gusle, Macedonian: гусла, Serbian: гусле, pronounced [ɡûsle]) is a primitive single-stringed musical instrument (and musical style) traditionally used in the Dinarides region of the Balkans (Southeastern Europe).

The instrument is always accompanied by singing; musical folklore, specifically epic poetry. The gusle player (guslar) 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.

The term gusle/gusli/husli/husla is common term to all Slavic languages and denotes a musical instrument with strings. The gusle should, however, not be confused with the Russian gusli, which is a psaltery-like instrument; nor with the Czech term for violin, housle.

The varieties of the guslar music are based on cultural basis; the content of each group is different, as different epic poems are used to accompany the instrument. Vocality provides the main difference to be found across every region concerning Bosnia and Herzegovina, Croatia, Montenegro and Serbia, while Albanians also use the Albanian language. The instrument itself is identical, only the design of the neck and head changes; the Serbian gusle has Serbian motif etc.