Chiron was notable throughout Greek mythology for his youth-nurturing nature. His personal skills tend to match those of his foster father Apollo, who taught the young centaur the art of medicine, herbs, music, archery, hunting, gymnastics, and prophecy, and made him rise above his beastly nature. Chiron was known for his knowledge and skill with medicine, and was thus credited with the discovery of botany and pharmacy, the science of herbs and medicine.

Like satyrs, centaurs were notorious for being wild, lusty, overly indulgent drinkers and carousers, violent when intoxicated. Chiron, by contrast, was intelligent, civilized, and kind, because he was not related directly to the other centaurs through his parentage. He was the son of the Titan Cronus and the Oceanid Philyra, and thus possibly brother to Dolops and Aphrus, the ancestor and eponym of the Aphroi (the native Africans). Chiron lived predominantly on Mount Pelion; there he married the nymph Chariclo, who bore him three daughters, Hippe (also known as Melanippe, the "black mare," or Euippe, "good mare"), Endeïs, and Ocyrhoe, and one son, Carystus. A different source states that his wife was called Nais, while a certain Aristaeus was called his son.

Like the other centaurs, Chiron was later expelled by the Lapithae from his home; but sacrifices were offered to him there by the Magnesians until a very late period, and the family of the Cheironidae in that neighbourhood, who were distinguished for their knowledge of medicine, were regarded as his descendants.

Although a centaur, Chiron's physical appearance often differs somewhat from other centaurs, demonstrating his status and heritage. In traditional Greek representations his front legs are human rather than equine, in contrast to the usual centaur with the entire lower body of a horse. This clearly sets Chiron apart and makes him easily identifiable, and may also have highlighted his unique lineage as the son of Cronus. He is often depicted carrying a branch with dead hares he has caught hanging from it, and is frequently shown wearing clothes, demonstrating that he is more civilized than a normal centaur (the only other occasional exceptions being the centaurs Nessus and Pholus).

The Education of Achilles wall painting, from the basilica in Herculaneum, is one of the most common Roman depictions of Chiron, showing him teaching Achilles the lyre. In this Roman version Chiron has a fully equine lower body, in contrast to the ancient Greek representations, and his ears match those of a satyr, folded over at the top, creating a more bestial figure closer to a standard centaur. It has been suggested that, with the rise of written sources, Roman artists were inspired by descriptions that simply used the word "centaur," rather than by traditional visual representations; this may reflect a lost nuance of the character in its migration from Greece to Rome rather than a deliberate reworking. Even so, Chiron retains an element of clothing and gains a laurel wreath, suggesting the artist wished to portray nobility or even divinity, consistent with the traditional view. It has also been suggested that this fresco reproduces an actual statue in the Roman forum.

According to an archaic myth, Chiron was sired by the Titan Cronus when he had taken the form of a horse and impregnated the nymph Philyra; in another version his mother was the nymph Naïs. Chiron's lineage differed from that of the other centaurs, who were born from Ixion (consigned to a fiery wheel) and Nephele, the "cloud" that, in the Olympian telling, Zeus had fashioned to look like Hera.

Soon after giving birth, Philyra abandoned her child out of shame and disgust. Chiron, effectively orphaned, was later found by the god Apollo, who took him under his wing and taught him music, the lyre, archery, medicine, and prophecy, while Apollo's twin sister Artemis trained him in archery and hunting. Chiron's uniquely peaceful character, kindness, and intelligence are attributed to Apollo and Artemis. Some sources speculate that he was originally a Thessalian god later subsumed into the Greek pantheon as a centaur.

A great healer, astrologer, and respected oracle, Chiron was said to be the first among centaurs and was highly revered as a teacher and tutor; among his pupils were many culture heroes, including Asclepius, Aristaeus, Actaeon, Achilles, Jason, and Medus. There is a persistent link with Peleus throughout Chiron's myth, explained by the fact that Peleus was Chiron's grandson through his daughter Endeis, who married Aeacus, king of Aegina. Chiron saved the life of Peleus when Acastus tried to have him killed by leaving him swordless in the woods to be slaughtered by the centaurs; Chiron retrieved the sword for Peleus and then explained how to capture the nymph Thetis, leading to their marriage. Chiron is also connected with the story of the Argonauts, whom he received kindly when they came to his residence on their voyage, for many of the heroes were his friends and pupils.

Chiron was a renowned mentor who brought up several future heroes. Achilles was the son of the Argonaut Peleus and the Nereid Thetis; Peleus, having already been saved by Chiron from Acastus and a band of murderous centaurs, brought Achilles to him when the boy was old enough. Chiron received Achilles as a disciple and fed him the innards of lions and boars and bear marrow; in some accounts Achilles was previously called "Ligyron" and Chiron gave him his new name. Later, Achilles taught Patroclus what Chiron had taught him, including the medical arts.

Aristaeus, though his mother Cyrene lived in Libya, was brought by his father Apollo to Mount Pelion to be reared by Chiron, and later became a god of rustic arts such as beekeeping and cheesemaking. Actaeon, son of Autonoë and Aristaeus, became an excellent hunter through Chiron's lessons; after he saw Artemis bathing she turned him into a stag and his own hounds devoured him, and the grieving dogs came to Chiron's cave, where the centaur fashioned an image of Actaeon to soothe them.

Asclepius, the god of doctors, was saved from his mother Coronis's funeral pyre and brought to Chiron, who reared him and taught him the art of healing; when Chiron's daughter Ocyrhoe prophesied Asclepius's destiny, Zeus turned her into a mare. Jason, leader of the Argonauts, was in some versions raised by Chiron after his mother Alcimede pretended he was stillborn to hide him from Pelias. Jason's son Medus (also called Medeus or Polyxenus), whose mother was Medea, was likewise reared by Chiron and later became the first king of the Medes. Other pupils include Melanion, the Arcadian hunter who won Atalanta, and, according to Statius, Patroclus (though Homer contradicts this). According to Ptolemy Hephaestion, Chiron also mentored the god Dionysus and a youth named Cocytus, though Photios I, who preserved Ptolemy's account, harshly criticized him as a distorter and inventor of myths.

Chiron's nobility is reflected in the story of his death: although immortal, he willingly relinquished his immortality after being incurably wounded, an act that allowed Zeus to release Prometheus from his punishment for giving fire to humankind. As the son of Cronus he could not die naturally, so it was left to Heracles to negotiate the exchange with Zeus. Chiron was pierced by one of Heracles' arrows treated with the blood of the Hydra (or, in other versions, with poison Chiron had himself given Heracles during his tutelage).

According to a scholium on Theocritus, this occurred during Heracles' visit to the cave of Pholus on Mount Pelion in the course of his fourth labour, the Erymanthian Boar. Heracles demanded wine, and Pholus reluctantly produced a vessel of sacred wine given by Dionysus to be kept in trust by the centaurs; when it was opened, its vapors intoxicated the wild centaurs led by Nessus, who attacked the cave with stones and fir trees. Heracles drove them back with Hydra-poisoned arrows, and during the assault Chiron was struck in the thigh. After the centaurs fled, the philosophical Pholus drew an arrow from a dead centaur, wondering how so small a thing could cause such destruction, and accidentally dropped it on his own hoof, dying instantly.

Ironically, Chiron, the master of the healing arts, could not heal himself and willingly gave up his immortality. Zeus took pity on his half-brother and placed him among the stars to be honored; the Greeks identified him as the constellation Centaurus. In Ovid's Fasti, Hercules visits Chiron's home on Pelion while the child Achilles is there, and one of the Hydra-venomed arrows falls and sticks in Chiron's left foot. Chiron tries in vain to heal himself with herbs, and after nine days, with a weeping Achilles looking on, he passes into the stars as a constellation.

A didactic poem, the Precepts of Chiron, has been lost, but fragments in heroic hexameters survive in quotations attributed to it. The common thread in the fragments, which may reflect to some degree the Acharnian image of Chiron and his teaching, is that they are expository rather than narrative: rather than recounting the inspiring events of archaic times as figures like Nestor or Glaucus might, Chiron taught the primeval ways of mankind, the gods, and nature, beginning with the caution, "First, whenever you come to your house, offer good sacrifices to the eternal gods."

The Achilleid was to be an epic poem on the life of Achilles, but its author, Statius, died while writing the second book late in the first century AD, during the reign of Domitian. The poem highlights the relationship between Chiron and his charge: in Book One, Thetis spends the evening with them in Chiron's cave on Mount Pelion before leaving with Achilles, and Chiron is shown in a paternal rather than merely instructional capacity, depicted as far from animal. Achilles fondly twines himself about the Centaur's shoulders, preferring his familiar bosom even with his mother present, and refers to Chiron as a parent (the Latin pater) when describing how he was fed.

This loving father-son theme, which the traditional view of Chiron never explored, may continue one begun by Ovid in the Fasti, where the dying Chiron is begged, "Live, I beg you; don't leave me, dear father!" — suggesting that in Rome the myth was reconfigured to present Chiron as a loving and loved foster parent. Book Two, however, shows Chiron as a strict and demanding teacher, making Achilles perform hard tasks such as standing in fast-flowing rivers and rebuking him to shame him; this duality reflects a traditional noble Roman education combining military and refined arts. Statius deliberately disassociates Chiron from the centaurs' famous battle with the Lapiths, describing his cave as holding no blood-tasted darts or weapons of festive combat, only those used for hunting, and emphasizing that Chiron fixed in Achilles' mind "the precepts of sacred justice."