Leuctra was a village of Boeotia in the territory of Thespiae, chiefly noticeable for the battle fought in its neighborhood in 371 BC between the Thebans and the Spartans and their allies.

A Peloponnesian army, about 10,000-11,000 strong, which had invaded Boeotia from Phocis, was here confronted by a Boeotian levy of perhaps 6000-7,000 soldiers under Epaminondas. In spite of inferior numbers and the doubtful loyalty of his Boeotian allies, Epaminondas offered battle on the plain before the town. Massing his cavalry and the 50-deep column of Theban infantry on his left wing, he sent forward this body in advance of his center and right wing.

The battle opened with the Spartans mercenary peltasts attacking and driving back the Boeotian camp followers and others who were reluctant to fight. After a cavalry engagement, in which the Thebans drove their enemies off the field, the decisive issue was fought out between the Theban and Spartan foot. The latter, though fighting well, were sent into disarray, when their retreating cavalry hopelessly disrupted Cleombrotus's attempt to outflank the Theban phalanx, and were themselves caught on their flank by Pelopidas and the Sacred Band of Thebes. The Spartans could not sustain in their 12-deep formation the heavy impact of their opponents' column, and were hurled back with a loss of about 1000 men, of whom 400 were Spartan citizens, including the king Cleombrotus I.

Seeing their right wing beaten, the rest of the Peloponnesians (unwilling participants) retired and left the enemy in possession of the field. The arrival of a Thessalian army under Jason of Pherae persuaded a relieving Spartan force under Archidamus not to heap folly on folly and to withdraw instead, while the Thebans were persuaded not to continue the attack on the surviving Spartans. But the battle is none the less of great significance in Greek history. It marks a revolution in military tactics, affording the first known instance of a deliberate concentration of attack upon the vital point of the enemy's line. Its political effects were equally far-reaching: The loss in material strength and prestige which the Spartans here sustained went part of the way in depriving them forever of their supremacy in Greece.