The Battle of Ager Falernus was a skirmish during the Second Punic War between the armies of Rome and Carthage. After winning the Battle of Lake Trasimene in Italy in 217 BCE, the army commanded by Hannibal marched south and reached Campania. The Carthaginians ultimately moved into the district of Falernum, a fertile river valley surrounded by mountains.

Quintus Fabius Maximus Verrucosus, who had been elected Roman dictator and commander of the Roman field forces after the disastrous defeat at Lake Trasimene, had dogged Hannibal and stuck to a strategy to fight only under favourable conditions. He now occupied all the river crossings and mountain passes leading out of the valley, thus blocking the Carthaginians inside.

After stripping the area of grain, cattle, and other supplies, Hannibal displayed brilliant tactics to provoke the Roman guard to leave one of the passes. Despite the protests of his staff officers, Fabius, who was camped near the pass with his main forces, refused to attack the Carthaginian army and it escaped the trap unscathed.