Cybele (/ˈsɪbəliː/ SIB-ə-lee; Phrygian: Matar Kubileya, Kubeleya 'Kubeleya Mother', perhaps 'Mountain Mother'; Lydian: Kuvava; Greek: Κυβέλη Kybélē, Κυβήβη Kybēbē, Κύβελις Kybelis) is an Anatolian mother goddess; she may have a possible forerunner in the earliest Neolithic at Çatalhöyük. She is Phrygia's only known goddess, and likely, its national deity. Greek colonists in Asia Minor adopted and adapted her Phrygian cult and spread it to mainland Greece and to the more distant western Greek colonies around the sixth century BC.

In Greece, Cybele met with a mixed reception. She became partially assimilated to aspects of the Earth-goddess Gaia, of her possibly Minoan equivalent Rhea, and of the harvest–mother goddess Demeter. Some city-states, notably Athens, evoked her as a protector, but her most celebrated Greek rites and processions show her as an essentially foreign, exotic mystery-goddess who arrives in a lion-drawn chariot to the accompaniment of wild music, wine, and a disorderly, ecstatic following. Uniquely in Greek religion, she had a eunuch mendicant priesthood, the Galli. Many of her Greek cults included rites to a divine Phrygian castrate shepherd-consort Attis, who was probably a Greek invention. In Greece, Cybele became associated with mountains, town and city walls, fertile nature, and wild animals, especially lions.

In Rome, Cybele became known as Magna Mater ("Great Mother"). The Roman state adopted and developed a particular form of her cult after the Sibylline oracle in 205 BC recommended her conscription as a key religious ally in Rome's second war against Carthage (218 to 201 BC). Roman mythographers reinvented her as a Trojan goddess, and thus an ancestral goddess of the Roman people by way of the Trojan prince Aeneas. As Rome eventually established hegemony over the Mediterranean world, Romanized forms of Cybele's cults spread throughout Rome's empire. Greek and Roman writers debated and disputed the meaning and morality of her cults and priesthoods, which remain controversial subjects in modern scholarship.

No contemporary text or myth survives to attest the original character and nature of Cybele's Phrygian cult. She may have evolved from a statuary type found at Çatalhöyük in Anatolia, of a "corpulent and fertile" female figure accompanied by large felines, dated to the 6th millennium BC and identified by some as a mother goddess. In Phrygian art of the 8th century BC, the cult attributes of the Phrygian mother-goddess include attendant lions, a bird of prey, and a small vase for her libations or other offerings.

The inscription Matar Kubileya/Kubeleya at a Phrygian rock-cut shrine, dated to the first half of the 6th century BC, is usually read as "Mother of the mountain", a reading supported by ancient classical sources, and consistent with Cybele as any of several similar tutelary goddesses, each known as "mother" and associated with specific Anatolian mountains or other localities: a goddess thus "born from stone". She is ancient Phrygia's only known goddess, the divine companion or consort of its mortal rulers, and was probably the highest deity of the Phrygian state. Her name, and the development of religious practices associated with her, may have been influenced by the Kubaba cult of the deified Sumerian queen Kubaba.

In the 2nd century AD, the geographer Pausanias attests to a Magnesian (Lydian) cult to "the mother of the gods", whose image was carved into a rock-spur of Mount Sipylus. This was believed to be the oldest image of the goddess, and was attributed to the legendary Broteas. At Pessinos in Phrygia, the mother goddess—identified by the Greeks as Cybele—took the form of an unshaped stone of black meteoric iron, and may have been associated with or identical to Agdistis, Pessinos' mountain deity. This was the aniconic stone that was removed to Rome in 204 BC.

Images and iconography in funerary contexts, and the ubiquity of her Phrygian name Matar ("Mother"), suggest that she was a mediator between the "boundaries of the known and unknown": the civilized and the wild, the worlds of the living and the dead. Her association with hawks, lions, and the stone of the mountainous landscape of the Anatolian wilderness, seem to characterize her as mother of the land in its untrammeled natural state, with power to rule, moderate or soften its latent ferocity, and to control its potential threats to a settled, civilized life. Anatolian elites sought to harness her protective power to forms of ruler-cult; in Phrygia, the Midas monument connects her with king Midas, as her sponsor, consort, or co-divinity. As protector of cities, or city states, she was sometimes shown wearing a mural crown, representing the city walls. At the same time, her power "transcended any purely political usage and spoke directly to the goddess' followers from all walks of life".

Some Phrygian shaft monuments are thought to have been used for libations and blood offerings to Cybele, perhaps anticipating by several centuries the pit used in her taurobolium and criobolium sacrifices during the Roman imperial era. Over time, her Phrygian cults and iconography were transformed, and eventually subsumed, by the influences and interpretations of her foreign devotees, at first Greek and later Roman.