Tehanu, initially subtitled The Last Book of Earthsea, is a fantasy novel by the American author Ursula K. Le Guin, published by Atheneum in 1990. It is the fourth novel set in the fictional archipelago Earthsea, following almost twenty years after the first three Earthsea novels (1968–1972), and not the last, despite its subtitle. It won the annual Nebula Award for Best Novel and the Locus Award for Best Fantasy Novel.

Ursula Kroeber Le Guin was an American author best known for her works of speculative fiction, including science fiction works set in her Hainish universe, and the Earthsea fantasy series. Her work was first published in 1959, and her literary career spanned nearly sixty years, producing more than twenty novels and over a hundred short stories, in addition to poetry, literary criticism, translations, and children's books. Frequently described as an author of science fiction, Le Guin has also been called a "major voice in American Letters". Le Guin said she would prefer to be known as an "American novelist".