king of Numidia who sided with the followers of Pompey and the Roman Senate in their war against Julius Caesar (Caesar, Julius) in North Africa (49–45 BC).

Succeeding his father, Hiempsal II, sometime between 63 and 50, Juba became bitterly hostile toward Caesar because of a personal insult (probably in 63). In addition, one of Caesar's supporters, the tribune Curio, in 50 unsuccessfully proposed the incorporation of Numidia as a Roman province. In 49, Curio landed in Africa to expel Pompey's forces but was defeated and killed by Juba, who thereupon considered himself the potential master of all North Africa.

Pompey died the following year, but African resistance continued under Metellus Scipio (to whom Juba was allied). In 46, Caesar himself came to subdue them. Juba had to divide his substantial army of infantry, cavalry, and elephants because his kingdom had been invaded from the west by Caesar's ally Bocchus, king of Mauretania, and an Italian adventurer, Publius Sittius. Juba was defeated with the other adherents of Pompey at Thapsus, and his general in the west was killed by Sittius. Repulsed from Utica by Cato (Uticensis) and expelled from his temporary capital Zama by its inhabitants, Juba committed suicide.