The Battle of Megalopolis was a battle near Megapolis, Greece in 331 BC between Spartan led forces commanded by King Agis III and Macedonia under command of Alexander's regent Antipater. It was a decisive Macedonian victory, effectively ending the Spartan revolt.

Early in the battle Antipater's lines broke, but in the end it was the sheer weight of numbers (doubling the enemies numbers) that brought victory to the Macedonians. It is written 5,300 died on the Spartan side and 3,500 on the Macedonian side. For the Spartans that meant a death toll of over 25 percent. King Agis, now wounded and unable to stand, ordered his men to leave him behind to face the advancing Macedonian army so that he could buy his men time to retreat. On his knees, the Spartan king slew several enemy soldiers before being finally killed by a javelin.