Stephanie Jane Swainston (born 1974) is a British literary fantasy/science fiction author, known for the Castle series.

Outside writing, Swainston has had a broad range of occupations, which include bookseller, archaeologist, lock keeper, information scientist, and pyrotechnician.

[1] Swainston's novels to date take place in the Fourlands, which the author has described as a secret childhood paracosm,[2][3] further influenced by aspects of her later adult life, including the competitive academic world.

[4] The novels centre on the life of the Circle, an elite group of immortals created and sustained by the Emperor, a near god-like figure engaged in a prolonged conflict with insect-like creatures, apparently from another world.

Swainston has argued against labeling writers, including herself, within genres, on the basis that good fantasy and mainstream literature form a continuum.