Anactoria (or Anaktoria; Ancient Greek: Ἀνακτορία) is a woman mentioned in the work of the ancient Greek poet Sappho. Sappho, who wrote in the late seventh and early sixth centuries BCE, names Anactoria as the object of her desire in a poem numbered as fragment 16. Another of her poems, fragment 31, is traditionally called the "Ode to Anactoria", though no name appears in it. As portrayed by Sappho, Anactoria is likely to have been an aristocratic follower of hers, of marriageable age. It is possible that fragment 16 was written in connection with her wedding to an unknown man. The name "Anactoria" has also been argued to have been a pseudonym, perhaps of a woman named Anagora from Miletus, or an archetypal creation of Sappho's imagination.

The English poet Algernon Charles Swinburne's "Anactoria" was published in his 1866 collection, Poems and Ballads. "Anactoria" is written from the point of view of Sappho, who addresses the title character in a long monologue written in rhyming couplets of iambic pentameter. The monologue expresses Sappho's lust for her in sexually explicit terms; she first rejects art and the gods for Anactoria's love before reversing her stance and claiming to reject Anactoria in favour of poetry. Swinburne's poem created a sensation by openly approaching then-taboo topics such as lesbianism and dystheism. Anactoria later featured in an 1896 play by H. V. Sutherland and in the 1961 poetic series "Three Letters to Anaktoria" by Robert Lowell, in which an unnamed man loves her before transferring, unrequitedly, his affections to Sappho.

Anactoria is named by the ancient Greek poet Sappho, who wrote in the late seventh and early sixth centuries BCE and is known for her love poetry, in fragment 16. Sappho compares her desire for Anactoria, who is described as being absent, with that of Helen of Troy for Paris. A second poem, fragment 31, is traditionally called the "Ode to Anactoria", though no name appears in it. It has also been speculated that Anactoria may be the unnamed character in fragment 96, written to another of Sappho's female companions, possibly Atthis. In that poem, Sappho claims that the unnamed character still "thinks of [Sappho] constantly" despite living away in the city of Sardis.

In the phrasing of Garry Wills, fragment 16 portrays Anactoria as "menacingly desirable". Sappho describes her manner of walking as attractive, and her face as having amarychma, a word literally meaning 'flashing' or 'sparkling' and likely also to indicate beauty in movement. Based on its allusions to other literary works, particularly those of Hesiod, the term may also indicate that Anactoria was a young, virgin girl of marriageable age. The Anactoria portrayed in Sappho's work is generally considered to have been a follower of Sappho, who educated aristocratic girls with the partial aim of preparing them for marriage.

A reference to "Anagora" in the Suda, a tenth-century Byzantine encyclopaedia, is generally considered to refer to Anactoria; the name "Anagora" has been interpreted as an error in the manuscripts, or alternatively by Denys Page as the real name of "Anactoria", to whom Page conjectures Sappho gave a pseudonym to protect her identity and reputation. The Suda names "Anagora" as a native of Miletus, a major Greek city of Ionia. Christopher Brown suggests that Anactoria's absence in fragment 16 was because she had left Sappho's company to return to Miletus and marry; Eric Dodson-Robinson suggests that fragment 16 may have been written for performance at Anactoria's wedding, or for a sympotic event shortly after it. However, George Koniaris suggests that Anactoria may equally have left Sappho's company to be with her family or to work as a musician, and Glenn Most points out that the poem gives no indication of the length of Anactoria's absence: he argues that it may only have been a matter of a few days. Martin West has argued that Sappho generally uses the name of the objects of her desire, such as Anactoria, when portraying their relationship with her as finished or her own attitude towards it as hostile.

Sappho's expressed love for Anactoria is one of few examples of a woman expressing same-sex desire to survive from pre-modern literature. Andrew Ford has argued that Sappho's presentation of Anactoria may be archetypal rather than a representation of any specific individual, while Judith Hallett and André Lardinois have suggested that the speaker may not have been intended as an autobiographical portrayal of Sappho herself. The classicist and archaeologist David Moore Robinson called the description of Anactoria in fragment 16 "the finest lines in all Sappho's poetry".

Anactoria is almost unattested in ancient sources outside Sappho's works. She is mentioned in a poem traditionally attributed to the first-century BCE Roman poet Ovid; the fifteenth of his Heroides. The poem is imagined as a letter from Sappho to her male lover Phaon, in which Sappho claims that her love for Phaon has made her former, female lovers, including Anactoria, seem worthless to her. In the second century CE, the rhetorician Maximus of Tyre compared the relationship between Sappho and Anactoria with that of the philosopher Socrates and his male acolytes such as Alcibiades. Both Maximus and the Suda list Anactoria as a favourite pupil of Sappho's.

The nineteenth-century English poet Algernon Charles Swinburne wrote a long poem, "Anactoria", published in his 1866 collection Poems and Ballads. The poem is written from the point of view of Sappho, who addresses Anactoria in a long monologue written in rhyming couplets of iambic pentameter, which incorporates fragments from Sappho's poetry: the poem's first line is "My life is bitter with thy love", which alludes to fragment 130. "Anactoria" presents Sappho's love and lust for Anactoria as the source of her poetic inspiration. In the conceit of the poem, Anactoria is about to leave Sappho, and Sappho initially longs for the goddess Aphrodite to return Anactoria to her. By the end, however, Sappho rejects Anactoria and the gods in favour of poetry, which she had initially proclaimed herself willing to sacrifice for Anactoria's love. Catherine Maxwell has described both Anactoria and Sappho as poetic representations of Swinburne himself.

The poem was both sensational and controversial for its treatment of taboo topics such as lesbianism, cannibalism and dystheism, as well as for its parody of both Sapphic and Biblical texts. Its content is sexually explicit and sadomasochistic; it was termed "frankly pornographic" in a 1971 article by David Cook. Swinburne's publication of "Anactoria", along with that of his "Sapphics", led to what Lawrence Lipking has termed his "ostracism". Catherine Maxwell and Stefano Evangelista have described "Anactoria" as both "infamous" and among Swinburne's most famous poems. Later critics have read it as a commentary on Romantic poetic authority, a critique of Victorian sexual and religious orthodoxies, and a meditation upon Sappho's position in history and literature.

While a student at Harvard University, H. V. Sutherland wrote a verse drama, Sappho, or Archilochus and Hipponax, which was performed by Harvard and Wellesley students in January 1896. In the play, Anactoria is initially loved by the poet Alcaeus, who leaves her for Sappho. In his 1961 collection Imitations, the American poet Robert Lowell wrote "Three Letters to Anaktoria", a series of poems including an adaptation of Sappho's fragment 31 as its first. In Lowell's poems, the unnamed, hypothetical man alluded to in fragment 31 becomes the main subject of the series: he loves Anaktoria, transfers his affections to Sappho, and later, in Lowell's words, "withdraws or dies". In painting, Anactoria's name is inscribed on one of the seats of the theatre depicted in the 1881 work Sappho and Alcaeus by Lawrence Alma-Tadema.