The Mercenary War, also known as the Truceless War, was a mutiny by troops that were employed by Carthage at the end of the First Punic War (264–241 BC), supported by uprisings of African settlements revolting against Carthaginian control. It lasted from 241 to late 238 or early 237 BC and ended with Carthage suppressing both the mutiny and the revolt.

The war began in 241 BC as a dispute over the payment of wages owed to 20,000 foreign soldiers who had fought for Carthage in Sicily during the First Punic War. When a compromise seemed to have been reached, the army erupted into full-scale mutiny under the leadership of Spendius and Matho. 70,000 Africans from Carthage's oppressed dependent territories flocked to join them, bringing supplies and finance. War-weary Carthage fared poorly in the initial engagements of the war, especially under the generalship of Hanno. Hamilcar Barca, a veteran of the campaigns in Sicily (and father of Hannibal Barca), was given joint command of the army in 240 BC; and supreme command in 239 BC. He campaigned successfully, initially demonstrating leniency in an attempt to woo the rebels over. To prevent this, in 240 BC Spendius and Autaritus tortured 700 Carthaginian prisoners to death (including Gisco), after which the war was pursued with great brutality on both sides.

By early 237 BC, after numerous setbacks, the rebels were defeated and their cities brought back under Carthaginian rule. An expedition was prepared to reoccupy Sardinia, where mutinous soldiers had slaughtered all Carthaginians. However, Rome declared that this would be an act of war and occupied both Sardinia and Corsica, in contravention of the recent peace treaty. This has been considered to be the single greatest cause of war with Carthage breaking out again in 218 BC in the Second Punic War.