Bolgios (Greek Βόλγιος, also Bolgius, Belgius) was a Gaulish leader during the Gallic invasion of the Balkans who led an invasion of Macedon and Illyria in 279 BC, killing the Macedonian king Ptolemy Keraunos. He was part of a force of Gauls settled in Pannonia who had advanced to Thrace under a leader called . Deciding on fresh conquests, they sent separate forces to different regions: one led by Cerethrius against the Thracians and Triballi; another against Paionia led by Brennus and Acichorius; and a third against the Macedonians and Illyrians, led by Bolgios.