The Labours of Hercules or Labours of Heracles (Ancient Greek: ἆθλοι, âthloi, Latin: Labores) are a series of tasks carried out by Heracles, the greatest of the Greek heroes, whose name was later romanised as Hercules. They were accomplished in the service of King Eurystheus. The episodes were later connected by a continuous narrative.

The establishment of a fixed cycle of twelve labours was attributed by the Greeks to an epic poem, now lost, written by Peisander (7th to 6th centuries BC).

Having tried to kill Heracles ever since he was born, Hera induced a madness in him that made him kill his wife and children. Afterwards, Heracles went to the Oracle of Delphi to atone, where he prayed to the god Apollo for guidance. Heracles was told to serve Eurystheus, king of Mycenae, for ten years. During this time, he was sent to perform a series of difficult feats, called labours.

Heracles was the son born by the mortal woman Alcmene after her affair with Zeus, the king of the gods, who had disguised himself as her husband Amphitryon. Alcmene, fearing the jealousy of Zeus's wife Hera, exposed her infant son, who was taken by either Zeus or his daughter Athena (the protectress of heroes) to Hera, who did not recognize Heracles and nursed him out of pity. Heracles sucked so strongly that he caused Hera pain, and when she pushed him away, her milk sprayed across the heavens, forming the Milky Way. But with divine milk, Heracles had acquired supernatural strength. Either Zeus or Athena brought the infant back to his mother, and he was subsequently raised by his parents. The child was originally given the name Alcides by his parents; it was only later that he became known as Heracles in an unsuccessful attempt to mollify Hera, with Heracles meaning Hera's "pride" or "glory". He and his mortal twin, Iphicles, were just eight months old when Hera sent two giant snakes into the children's chamber. Iphicles cried from fear, but his twin brother grabbed a snake in each hand and strangled them. He was found by his nurse playing with them on his cot as if they were toys. Astonished, Amphitryon sent for the seer Tiresias, who prophesied an unusual future for the boy, saying he would vanquish numerous monsters.

Heracles married Megara, eldest daughter of King Creon of Thebes. However, in a fit of madness induced by Hera, Heracles killed Megara and their children. According to Euripides's play Herakles, however, it was not until after Heracles had completed his labours and on his return from the Underworld that he murdered Megara and his children.

After recovering his sanity, Heracles deeply regretted his actions; he was purified by King Thespius, then traveled to Delphi to inquire how he could atone for his actions. Pythia, the Oracle of Delphi, advised him to go to Tiryns and serve his cousin, King Eurystheus of Mycenae, for twelve years, performing whatever labours Eurystheus might set him; in return, he would be rewarded with immortality. Heracles despaired at this, loathing to serve a man whom he knew to be far inferior to himself, yet fearing to oppose his father, Zeus. Eventually, Heracles placed himself at Eurystheus's disposal.

Of the twelve labours performed by Heracles, six were located in the Peloponnese, culminating with the rededication of Olympia. Six others took the hero farther afield, to places that were, according to Ruck and Staples, "all previously strongholds of Hera or the 'Goddess' and were entrances to the Netherworld". In each case, the pattern was the same: Heracles was sent to kill or subdue, or to fetch back for Eurystheus (as Hera's representative) a magical animal or plant.

A famous depiction of the labours in Greek sculpture is found on the metopes of the Temple of Zeus at Olympia, which date to the 460s BC.