Seanan McGuire (pronounced SHAWN-in) is an American author and filker. She is renowned for her urban fantasy novels and writes under several pseudonyms, including Mira Grant for science fiction/horror and A. Deborah Baker for the "Up-and-Under" children's portal fantasy series.

In 2010, McGuire was honored with the John W. Campbell Award for Best New Writer by the World Science Fiction Convention. Her 2016 novella Every Heart a Doorway was awarded the Nebula Award, Hugo Award, Locus Award, and Alex Award.

In 2013, she achieved a record five Hugo nominations, with two under the pseudonym Mira Grant and three under her own name. McGuire often includes numerous queer characters in her works.