Diviciacus or Divitiacus was a druid of the Aedui tribe who lived in Gaul during the 1st century BC. He is the only druid from antiquity whose existence is attested by name. The name may mean "avenger". His date of birth is unknown, though he was an adult during the late 60s BC, and an aristocrat who took part in the clans' decision-making, as described by Julius Caesar in Caesar's The Gallic War.

The Gallic Wars were waged between 58 and 50 BC by the Roman general Julius Caesar against the peoples of Gaul. Gallic, Germanic, and Brittonic tribes fought to defend their homelands against an aggressive Roman campaign. The Wars culminated in the decisive Battle of Alesia in 52 BC, in which a complete Roman victory resulted in the expansion of the Roman Republic over the whole of Gaul. Though the collective Gallic armies were as strong as the Roman forces, the Gallic tribes' internal divisions eased victory for Caesar. Gallic chieftain Vercingetorix's attempt to unite the Gauls under a single banner came too late. Caesar portrayed the invasion as being a preemptive and defensive action, but historians agree that he fought the wars primarily to boost his political career and to pay off his debts. Still, Gaul was of significant military importance to the Romans. Native tribes in the region, both Gallic and Germanic, had attacked Rome several times. Conquering Gaul allowed Rome to secure the natural border of the river Rhine.