At the beginning of the poem, Ovid addresses the gods and asks them to bless his undertaking. Then he begins his tale of transformations by describing how the earth, and the heavens and everything else were created out of chaos. He describes how mankind progressed (or degenerated) from the Gold Age to the Silver Age to the Age of Iron. The bad behavior of mankind lead to an attempt by the giants to seize the heavens. In response to all this corruption, Jove sends a great flood to the earth which destroys all living things except one pious couple: Deucalion and Pyrrha. After the floods, this couple repopulates the earth by obeying the commands of the gods and throwing rocks behind them; these rocks transform into a new, hearty breed of man.
Ovid turns to the tale of Daphne and Apollo, and how Apollo's unrequited love leads Daphne to be transformed into a laurel tree. At the same time, Inachus the river god's daughter, Io, has been raped by Jove, who then transforms Io into a cow to protect her from jealous Juno. Suspicious, Juno takes possession of the cow, and Ovid goes on to describe how Jove sends mercury to kill Argus, Io's guard, and how Io must flee Juno's wrath until Jove forces Juno to pardon her. Io's son becomes friends with a boy named Phaethon, the son of Apollo. When Epaphus does not believe in Phaethon's parentage, Phaethon goes to his father to seek proof. His desire for proof leads to his downfall - he forces his father to allow him to drive the chariot of the sun, but he cannot control it and he is killed. His sisters are so distraught, they are transformed into trees. Even his friend Cycnus become swan in his grief. While Jove repairs the destruction Phaethon's ride caused, he spots the beautiful nymph Callisto, one of Diana's handmaids. He rapes her, and Diana discovers her impurity, she is banished. After she gives birth she is transformed by Juno into a bear. When her son is fifteen he almost kills her, and Jove transforms them into constellations, to Juno's fury.
Next Ovid tells a story of how the Raven became black due to the evils of gossip, the transformation of Ocyrhoe, the prophetess, into stone; and the story of how Mercury turned a shepherd into stone for betraying a secret. Mercury then falls in love with the beautiful Herse, which results in Herse's sister, Aglauros, being turned to stone for her envy. At the same time, Jove falls in love with the princess Europa, and, disguised as a bull, he carries her off. When Europa's brother goes to search for her and cannot discover her, he founds a new city and creates a new people by sewing the ground with the teeth of a serpent. He rules his warrior people well, and their line is happy, until the misfortune of his grandson, Actaeon. Actaeon inadvertently stumbles upon Diana bathing; Diana turns him into a stag, and he is hunted by his own men and torn apart by his own dogs. Juno is pleased by this misfortune, but also distracted by the fact that another women, Semele, is about to give birth to Jove's child. She tricks Semele into forcing Jove to let her see him in all his glory, and the sight destroys Semele. The child is saved, a boy named Bacchus, who will go on to become a god.
One day Jove and Juno are arguing about who takes more pleasure from love, men or women. Tiresias, who has been both a man and a woman, settles the argument and agrees with Jove, saying that women get more pleasure out of acts of love. Juno blinds him in response, but Jove gives him the gift of prophecy. Tiresias's prediction of Narcissus's early death cements his reputation, when Narcissus falls in love with his own reflection and he wastes away into a flower. Tiresias also predicts the death of Pentheus, whose refusal to properly worship the gods is punished by his being torn apart by his sisters and mother when they are in the throes of the Bacchic rites. Next Ovid tells of others who refuse to worship gods, specifically the daughters of Minyas who reject the divinity of Bacchus. During one festival of the god, they refuse to participate and instead stay inside exchanging stories such as the tale of Pyramus and Thisbe, the discovery of Venus and Mercury's adultery, and the creation of the Hermaphrodite. That night the women are turned into bats for trying to hide in the shadows away from divine eyes. Juno, furious that Bacchus is worshipped as a divinity, punishes the house of his forefathers, driving some mad and pursuing others. Cadmus and his wife are saved only by their transformation into snakes.
Another man, Acrisius, also objects to the divinity of Bacchus, as well as the divinity of Perseus, though he is forced later to repent. Perseus uses the head of Medusa to fill Acrisius's land with serpents born from drops of her blood. He then turns Atlas into stone and saves Andromeda from a monstrous sacrifice. At their wedding feast, he tells the origin of Medusa. The wedding party ends in a terrible battle when Andromeda's previous intended husband opposes her marriage to Perseus, but in the end Perseus destroys all who try and fight against him. Now Minerva leaves her brother and goes to see the spot where Pegasus (born from Medusa's blood) created a fountain with a stomp of his foot. While there, the muses tell her a story of their dreadful encounter with King Pyreneus, who tried to capture them but was killed by his own foolish actions. The muses also tell her a story of nine sisters who challenged them to a singing contest and were turned to birds when they lost.
Jove tells the story of Arachne, who challenged Minerva to a contest of spinning, and was punished for her insolence (and for her talent) by being transformed into a spider. Niobe heard this tale, but she did not profit from it. She openly declares she is more fit to be worshipped as a goddess than Latona, emphasizing her numerous progeny. As punishment, all of Niobe's children are killed, and Niobe turns to stone. A group of men tell stories of how Latona punished men who were rude to her by turning them into frogs, and how Apollo flayed a satyr for daring to challenge his superiority as a musician.
Kings from many lands come to pay their respects to Amphion and his children, but not to Niobe; Athens, which is at war, is alone unrepresented. Tereus of Thrace helps them win and marries Procne as his reward. Five years later, Tereus meets Procne's sister, Philomela, and immediately lusts after her; he kidnaps her and tells Procne that she died. When Philomela resists the rape, Tereus cuts out her tongue to keep her from accusing him. Philomela still manages to inform her sister, however, and in revenge for the rape Procne kills her son with Tereus, cooks his body, and feeds it to his father. Tereus tries to kill them, but they all turn into birds as he pursues them. Philomela's father dies at the news, and the kingdom passes to Erectheus. One of his daughters, Orithyia, marries the god of the north wind, Boreas. Their sons sail with the Argonauts for the golden fleece.
When Jason arrives at the land of King Aeetes, the king's daughter Medea falls in love with him and aids him. They depart together as husband and wife, and when they arrive home to find that Jason's father is deathly ill, Medea magically cures him, only to trick his daughters into killing him so that Jason can claim his throne. She flees to escape punishment, and when she returns to Jason, she discovers he has a new wife. In revenge, Medea kills Glauce, his new bride, as well as her own two sons by Jason. She receives sanctuary from a new husband, Aegeus of Athens, only to leave after she almost kills Aegeus's unknown son, Theseus. Now Aegeus turns his attention to the threat of King Minos of Crete, who is looking to avenge the death of his son. He sends Cephalus to seek the help of the people of Aegina. When Cephalus arrives, he learns that the Aegina was decimated, but that Jove blessed their ruler with the creation of a new race of people, and King Aegeus promises these men will serve him bravely and well. Before he leaves, Cephalus tells the princes the story of how jealousy eventually destroyed his marriage. First he describes how his own jealousy of his wife led him to test her unfairly and almost destroyed his marriage, and then he explains how a foolish misunderstanding by his wife led him to accidentally kill her while hunting in the forest.
Cephalus returns to Athens with the promised army. Unfortunately, the king's daughter, Scylla, betrays the city to Minos, who she loves. Minos does not reciporicate her affection but has a strange wife of his own who is in love with a bull. She gives birth to a half-man, half-bull creature, the minotaur, who Minos hides away in a labyrinth designed by Daedalus. Minos requires Athens to send an Athenian youth every nine years as a sacrifice for the minotaur. By the time of the third tribute, Theseus is chosen, but he is saved by the love of princess Ariadne, who aids hi through the labyrinth. He kills the minotaur and they sail away together; Theseus abandons Ariadne in Dia, and Bacchus transforms her into a constellation. Meanwhile, Daedalus plots to escape Crete with his son Icarus by flying through the sky on wings made of feathers and wax. Despite his father's warning, Icarus flies too close to the sun, the wax in his wings melts, and he falls to his death.
Theseus and other brave Greeks converge in Calydon to fight a wild boar sent by Diana to punish the king for neglecting her tribute. King Oeneus's son slays the boar, but he gives the spoils to Atalanta, who drew the first blood. He kills his uncles when they object. Alcatha, his mother, kills her son and then herself, and his sisters are so distraught that Diana turns them into birds. On his way back to Athens, Theseus takes shelter during a storm at the home of Achelous, a river god, where he hears many stories including the tale of how Achelous lost one of his horns, limiting his power to change shape. Hercules tore it from his head in a battle for the hand of Deianira. The centaur Nessus later attacks them, only to be killed by Hercules. Before he dies, he convinces Nessus that his shirt has the power to restore love, when in fact it is cursed. Years later, when Deianira fears Hercules is in love with someone else, she gives him the shirt. Hercules is consumed by pain and sets himself afire. Thus he burns away his mortal and becomes a god.
Ovid turns to the story of twins, Byblis and Caunus; Byblis confesses an incestuous passion for Caunus, who flees upon hearing of it. She follows, but eventually her grief turns her into a fountain. We then hear of a man named Ligdus, whose wife is forced to disguise her daughter as a son rather than put her to death. They call "him" Iphis. Iphis falls in love with a girl, and the gods intercede, changing "him" into an actual boy. Ovid turns to Hymen, who fails to bless the Orpheus and Eurydice. As a result, Eurydice dies, but Orpheus is given a chance to restore her life, which fails. Orpheus then sings sad tales, such as Jove's theft of Ganymede from his wife, the death of Hyacinthus, and the transformation of Ganymede, a statue sculpted by Pygmalion, into a real woman. Next he tells of Myrrha, who loves her own father. She sleeps with him many nights, only to discover that he has been sleeping with his daughter. She flees, pregnant. The gods out of pity turn her into a myrrh tree, and her baby tumbles from a split in the tree. This child grows up to be the beautiful Adonis, whom Venus falls in love with. She tells him the story of how Hippomenes won Atalanta by using golden apples to beat her in a race. He forgot to thank Venus for help in this affair, and as a result he and Atalanta were turned into lions, thus Adonis must always avoid lions and beasts like them. Soon after Adonis is killed while hunting a boar; Venus turns his body in an anemone. Women in a bacchic frenzy tear Orpheus to pieces as he sings. In punishment, Bacchus turns them to oak trees. Ovid then turns to the familiar story of King Midas, whose touch turns his daughter to gold.
Next Apollo and Neptune help King Laomedon found Troy. When he refuses the promised payment they flood the surrounding area. Hercules seizes the city and his companion, Telamon, marries the princess Hesione. Telamon's brother, Peleus, marries the goddess Thetis with Proteus' help. Peleus kills his brother Phocus flees with Thetis to Tracin, where a wolf haunts them for the murder of Phocus. Ovid turns to Ceyx and his wife, Alcyone: when he is killed in a storm, she is desperate with grief and walks the beach. One day, she sees Ceyx's body drift ashore on a piece of driftwood. As she rushes to meet it, she and the body are both transformed into birds, Halcyons.
Ovid then turns to the famous Trojan War. Paris steals Helen, the most beautiful woman in the world, and Helen's wife Menaleus raises an army to take her back. During a lapse in the battle, we overhear the Greeks telling stories. Nestor tells of Caenis, an invincible woman transformed into a man, who intervened at the wedding of Pirithous and Hippodame when Centaurs tried to carry of the bride. The Centaurs bury Caenis beneath a huge mound of trees and rocks. The story of the war continues and Ovid recounts Achilles' death, the dispute over his armor and the fall of Troy. After the war, the spirit of Achilles forces Agamemnon to sacrifice Polyxena, Hecuba and Priam's daughter. Hecuba kills Polymestor in rage, and when his followers try to punish her, she is transformed into a dog.
A Trojan prince, Aeneas, escapes the fall and travel through the Mediterranean, facing many obstacles. They spend a great deal of time in Carthage, where Dido falls in love with Aeneas lover; she kills herself when he abandons her. Aeneas undergoes further adventures, many of which are also reconted in Virgil's Aeneid, before he and his men finally arrive at the kingdom of Latinus, where Aeneas wins a new bride, Lavinia, and a new kingdom. Venus convinces Jove to make Aeneas a divinity and Jove agrees. Aeneas' son, Julus, becomes king.
Generations later, Amulius unjustly seizes Latinus, but Numitor and his grandson Romulus recapture it and found the city of Rome. The Sabines attack, and with Juno's aid they almost enter the city; but in the end Venus prevents them. The Romans and Sabines fight, and eventually the Romans agree to let the Sabines share the city, which will be jointly ruled by Tatius and Romulus. After Tatius's death, Romulus is made a god, his wife Hersilia a goddess. Numa becomes king of Rome; he has been trained by Pythagoras and relates many of the famous philosopher's teachings and prophesies. Under Numa's rule, Rome prospers in the art of peace. When he dies, his wife Egeria is so mournful that Diana transforms her into a fountain.
Approaching the present day Rome of which Ovid is a patron, we learn the stories of Cipus, a man who tries selflessly to resist ruling Rome, and of Aesculapius, who cures Rome of a nasty plague. The god Caesar arises in Rome after the plague passes. Ovid declares that Caesar's greatest achievement was to father Augustus, the current emperor of Rome. As he closes his work, Ovid asks that time pass slowly until Augustus's death. Ovid glories in the fact that so long as the city of Rome survives, his own work will survive.