Hippomenes was born in Onchestus, a city in Boeotia in central Greece, the son of Megareus, the king of that city, and his queen. In some accounts his father is called Onchestus, the eponymous hero of the city, or Amphidamas, a Boeotian nobleman. Whatever his exact parentage, Hippomenes grew up in a land famous for its horses and its speed, and he was himself a runner of exceptional talent, though he was not arrogant enough to believe that talent alone could match the woman he desired. The woman was Atalanta, the daughter of Schoeneus, the king of Arcadia, or in some versions of Iasus, the king of the same region. Atalanta had been exposed on a mountainside as an infant because her father wanted a son, and she had been raised by a she-bear and trained by Artemis, the virgin goddess of the hunt, to become the most skilled huntress and the fastest runner in all Greece. She had sailed with the Argonauts, the crew of the ship Argo who sought the Golden Fleece, and she had wounded the Calydonian Boar, the monstrous creature sent by Artemis to ravage Calydon. When she came of age, her father demanded that she marry, and she agreed on one condition: any suitor who wished to wed her must first defeat her in a footrace. Those who lost would die by her hand.

Many men had tried. Princes from across Greece came to Arcadia to race the maiden, drawn by her beauty and her fame, and every one of them lost. Atalanta ran like the wind, her feet barely touching the ground, and when she passed her suitors she turned and killed them with a spear or a sword, leaving their bodies on the plain as a warning to the next fool who thought love could outrun death. Eighteen or twenty or thirty men died in this way, the numbers varying with the teller, and the pile of corpses grew so large that the racecourse itself became a graveyard. Hippomenes watched the races from the crowd, and he fell in love with Atalanta not merely for her beauty but for her terrible freedom, the absolute autonomy that no other woman in Greece possessed. He decided to compete, though he knew he could not outrun her.

Before the race, Hippomenes prayed to Aphrodite, the goddess of love, whose power was older than Artemis's and more cunning than Athena's. He asked for her help, and the goddess, who loved nothing more than to unite lovers who seemed impossible to match, gave him three golden apples from the garden of the Hesperides, the nymphs of the western evening who tended the tree of golden fruit that Gaia, the earth-goddess, had given to Hera as a wedding gift. The apples were divine, heavier than they looked, and their radiance was so beautiful that anyone who saw them would desire to possess them. Aphrodite instructed Hippomenes to drop the apples one by one during the race, and Atalanta's desire for the golden fruit would slow her down enough for him to reach the finish line first.

The race began. Atalanta and Hippomenes stood at the starting line, the suitors stripped to their racing tunics, the maiden in her hunting dress, and the crowd held its breath. Atalanta let Hippomenes take the lead, as she always did with her suitors, enjoying the moment when she would overtake them and strike them down. But when she drew near, Hippomenes rolled the first golden apple across her path. Atalanta saw it, and her desire for the beautiful thing overcame her competitive focus. She veered from the track, picked up the apple, and resumed the race, but Hippomenes had gained precious ground. She overtook him again, and he threw the second apple, wider this time, forcing her to run further off course. She retrieved it, cursing her own weakness, but now Hippomenes was near the finish line. She sprinted to catch him, her divine speed closing the gap, but he hurled the third apple directly into the crowd, and Atalanta, unable to resist, plunged after it while Hippomenes crossed the finish line and won her hand.

They married and had a son, Parthenopaeus, who grew up to be one of the Seven Against Thebes, the champions who attacked the cursed city in the generation before the Trojan War. But the marriage did not last in human form. Hippomenes had won Atalanta through the help of a goddess, and he had failed to thank Aphrodite with sacrifices after his victory, a neglect that the goddess never forgave. She filled him with an uncontrollable desire to make love to his wife in a place of worship, and one day, as they travelled through Boeotia, they entered a temple of Zeus on Mount Cithaeron, or in some accounts a shrine of Cybele, the mother goddess of Asia Minor, and there they lay together on the sacred ground. The god was enraged by this desecration, and he transformed both of them into lions, the beasts that the Greeks believed did not mate with one another but only with leopards, a biological impossibility that made their union forever impossible. They lost their human minds, their human speech, and their human love, and they wandered the mountains of Boeotia as beasts until they died or were killed by hunters.