Despoina or Despoena (/dɛsˈpiːnə/;[1] Greek: Δέσποινα, romanized: Déspoina) was the epithet of a goddess worshipped by the Eleusinian Mysteries in Ancient Greece as the daughter of Demeter and Poseidon and the sister of Arion.

[2] Surviving sources refer to her exclusively under the title Despoina ("the Mistress," cognate of "Despot") alongside her mother Demeter, as her real name could not be revealed to anyone except those initiated into her mysteries and was consequently lost with the extinction of the Eleusinian religion.

[5] The second element is derived from the hypothetical PIE form *pot-niha-, "mistress", "lady", "wife", is the feminine counterpart to *pótis, "husband"; cf.

[9] In Modern Greek the title "despoinis" (δεσποινίς) means "Miss", literally "little mistress", and can be used to address young ladies and waitresses, amongst others.

[11] Wanax was her male companion (paredros) in the Mycenean cult, and usually, this title was applied to the god Poseidon as king of the sea.

[12] In the myth of the isolated land of Arcadia, Poseidon appears as a beastly horse which represents the river spirit of the underworld.

[18] On a marble relief at Lycosura is the veil of Despoina, on which human figures are represented with the heads of different animals, seemingly, in a ritual dance.

[19][20] Similar processions of daemons or human figures with animal masks appear on Mycenean frescoes and gold rings.

In Arcadia Poseidon was closely related to the pair of Arcadian great goddesses identified as Demeter and Kore.

[25] She was known by the additional epithet of Despoine among the general population, just as they surnamed Demeter's daughter by Zeus as Kore (the maiden).

[26][27] Women who worshiped at the site had to adhere to a dress code that prohibited participants from wearing black or purple, possibly because those colours were worn by priestesses.

Her epithet, "the mistress", has its analogue in Mycenean Greek inscriptions found at Pylos in southern Greece and at Knossos in Crete.

The most significant artifact among its collection is the veil of Despoina, displaying a complex decorative program, probably representative of the types of embroidered woven materials created by contemporary artists.