In ancient Greek religion and mythology, Hestia (/ˈhɛstiə, ˈhɛstʃə/; Ancient Greek: Ἑστία, lit. 'hearth, fireplace, altar') is the virgin goddess of the hearth and the home. In myth, she is the firstborn child of the Titans Cronus and Rhea, and one of the Twelve Olympians.

In Greek mythology, newborn Hestia, along with four of her five siblings, was devoured by her father Cronus, who feared being overthrown by one of his offspring. Zeus, the youngest child, escaped with his mother's help, and made his father disgorge all his siblings. Cronus was supplanted by this new generation of deities; and Hestia thus became one of the Olympian gods, the new rulers of the cosmos, alongside her brothers and sisters. In spite of her status, she has little prominence in Greek mythology. Like Athena and Artemis, Hestia elected never to marry and remained an eternal virgin goddess instead, forever tending to the hearth of Olympus.

As the goddess of sacrificial fire, Hestia received the first offering at every domestic sacrifice. In the public domain, the hearth of the prytaneum functioned as her official sanctuary. Whenever a new colony was established, a flame from Hestia's public hearth in the mother city would be carried to the new settlement. The goddess Vesta is her Roman equivalent.

Hestia's name means "hearth, fireplace, altar". This stems from the PIE root *wes, "burn" (ultimately from *h₂wes- "dwell, pass the night, stay"). It thus refers to the oikos: domestic life, home, household, house, or family. Burkert states that an "early form of the temple is the hearth house; the early temples at Dreros and Prinias on Crete are of this type as indeed is the temple of Apollo at Delphi which always had its inner hestia". The Mycenaean great hall (megaron), like Homer's hall of Odysseus at Ithaca, had a central hearth. Likewise, the hearth of the later Greek prytaneum was the community and government's ritual and secular focus. Hestia's naming thus makes her a personification of the hearth and its fire, a symbol of society and family, also denoting authority and kingship.

Hestia is a goddess of the first Olympian generation. She is the eldest daughter of the Titans Rhea and Cronus, and sister to Demeter, Hades, Hera, Poseidon, and Zeus. Immediately after their birth, starting with Hestia, Cronus swallowed each of them, but their mother deceived Cronus and helped Zeus escape. Zeus forced Cronus to disgorge his siblings and led them in a war against their father and the other Titans.

Karl Kerenyi interprets the lines from the Homeric Hymn to Aphrodite (composed around the eighth or seventh century BC) that Hestia is simultaneously the eldest and youngest Cronid to mean that because she was the first to be devoured and (presumably) the last to be yielded up again, Hestia thus counts as both the eldest and youngest daughter of her parents. It is more likely that the anonymous author of the hymn was trying to reconcile the two conflicting birth orders given by Hesiod and Homer; while in the Theogony the firstborn is Hestia, in the Iliad Hera states that she is the eldest child.

Zeus assigned Hestia a duty to feed and maintain the fires of the Olympian hearth with the fatty, combustible portions of animal sacrifices to the gods. Wherever food was cooked, or an offering was burnt, she thus had her share of honor; also, in all the temples of the gods, she has a share of honor. "Among all mortals, she was chief of the goddesses".

The gods Poseidon and Apollo (her brother and nephew respectively) both fell in love with Hestia and vied for her hand in marriage. But Hestia would have neither of them, and went to Zeus instead, and swore a great oath, that she would remain a virgin for all time and never marry. In the Homeric Hymn to Aphrodite, Aphrodite (goddess of sex and love) has "no power" over Hestia.