Ēostre (Proto-Germanic: *Austrō(n)) is a West Germanic spring goddess. The name is reflected in Old English: *Ēastre ([ˈæːɑstre]; Northumbrian dialect: Ēastro, Mercian and West Saxon dialects: Ēostre [ˈeːostre]), Old High German: *Ôstara, and Old Saxon: *Āsteron. By way of the Germanic month bearing her name (Northumbrian: Ēosturmōnaþ, West Saxon: Ēastermōnaþ; Old High German: Ôstarmânoth), she is the namesake of the festival of Easter in some languages. The Old English deity Ēostre is attested solely by Bede in his 8th-century work The Reckoning of Time, where Bede states that during Ēosturmōnaþ (the equivalent of April), pagan Anglo-Saxons had held feasts in Ēostre's honour, but that this tradition had died out by his time, replaced by the Christian Paschal month, a celebration of the resurrection of Jesus.

Additionally, scholars have linked the goddess's name to a variety of Germanic personal names, a series of location names (toponyms), and, discovered in 1958, over 150 inscriptions from the 2nd century CE referring to the matronae Austriahenae, goddesses with connected names venerated on the European continent.

By way of linguistic reconstruction, the matter of a goddess called *Austrō(n) in the Proto-Germanic language has been examined in detail since the foundation of Germanic philology in the 19th century by scholar Jacob Grimm and others. As the Germanic languages descend from Proto-Indo-European (PIE), historical linguists have traced the name to a Proto-Indo-European goddess of the dawn *H₂ewsṓs, from which may descend the Common Germanic divinity at the origin of the Old English Ēostre and the Old High German Ôstara.

Theories connecting Ēostre with records of Germanic Easter customs, including hares and eggs, have been proposed. Whether the goddess was an invention of Bede has been a debate among some scholars, particularly prior to the discovery of the matronae Austriahenae and further developments in Indo-European studies. Ēostre and Ostara are sometimes referenced in modern popular culture and are venerated in some forms of Germanic neopaganism.