Neboulos (Greek: Νέβουλος) was a South Slavic or Bulgar military commander in the service of the Byzantine emperor Justinian II (r. 685–695 and 705–711), who defected with many of his men to the Arabs during the crucial Battle of Sebastopolis.In 688/9, Justinian II forcibly transplanted Slavic populations from the Balkans and settled them in the depopulated Opsician Theme.