king of the Masaesyli, a Numidian tribe (in North Africa). Formerly a Carthaginian dependent, he rebelled in 214 BC in consultation with Publius Cornelius Scipio (Scipio, Publius Cornelius) and his brother Gnaeus, who were fighting Carthaginian forces in Spain at the time. In 206 Syphax expelled his neighbour and rival Masinissa. When Syphax married Sophonisba—daughter of the Carthaginian commander Hasdrubal, son of Gisgo (Hasdrubal)—Syphax returned his allegiance to Carthage.

When Scipio Africanus (Scipio Africanus the Elder), the son of Publius, invaded Africa near the end of the Second Punic War (Punic War, Second), Syphax opposed him at Utica, on the coast of what is now Tunisia. Scipio burned Syphax's camp there, and Scipio's friend Gaius Laelius (Laelius, Gaius) defeated Syphax at the Battle of the Great Plains near Utica (203). Syphax fled to Numidia, where he was defeated and captured by Masinissa. He was handed over to the Romans and deported to Italy, where he died.