Perbundos (Greek: Περβοῦνδος, Perboundos) was a 7th-century king of the Rhynchinoi, a Slavic group in Macedonia. In ca. 675 he was taken prisoner by the Byzantine Empire due to his hostile intentions towards Thessalonica, and transported to Constantinople. Perbundos managed to escape, but was recaptured and executed, whereupon the Slavic tribes of Macedonia rose up and laid siege to Thessalonica.
Perbundos is attested only in the Miracles of Saint Demetrius, a 7th-century collection of homilies in praise of Saint Demetrius, the patron saint of Thessalonica, which provides much unique historical information about the collapse of Byzantine imperial authority and the Slavic settlement in the Balkans.
In the second book of the Miracles, Perbundos is called the "king of the Rhynchinoi" (ὀ τῶν Ῥυγχίνων ρῆξ), an apparently relatively powerful Slavic tribe living near Thessalonica. According to the Miracles, in ca. 675/6 he came to the attention of the Byzantine archon of Thessalonica as being hostile and planning an attack on the city. When informed, Emperor Constantine IV ordered his arrest, and during a visit to the city, Perbundos was seized, put in irons and sent to the Byzantine capital, Constantinople. The Rhynchinoi, along with the other Slavic tribes living in the Strymon valley (Strymonitai), sent envoys to the emperor seeking his release, and Constantine promised to let him go once the war with the Arabs was over.