Emma Bull (born 13 December 1954) is a science fiction and fantasy author whose best-known novel is War for the Oaks, one of the pioneering works of urban fantasy. She has participated in Terri Windling's Borderland shared universe, which is the setting of her 1994 novel Finder. She sang in the rock-funk band Cats Laughing, and both sang and played guitar in the folk duo The Flash Girls while living in Minneapolis, Minnesota.
Her 1991 post-apocalyptic science fiction novel Bone Dance was nominated for the Hugo, Nebula, and World Fantasy Awards. Bull wrote a screenplay for War for the Oaks, which was made into an 11-minute mini-film designed to look like a film trailer. She made a cameo appearance as the Queen of the Seelie Court, and her husband, Will Shetterly, directed. Bull and Shetterly created the shared universe of Liavek, for which they have both written stories. There are five Liavek collections extant.
She was a member of the writing group The Scribblies, which included Will Shetterly as well as Pamela Dean, Kara Dalkey, Nate Bucklin, Patricia Wrede and Steven Brust. With Steven Brust, Bull wrote Freedom and Necessity (1997), an epistolary novel set during the 19th century United Kingdom of Great Britain and Ireland Chartist movement.
She is Executive Producer and one of the writers for Shadow Unit, along with Elizabeth Bear, Sarah Monette, Will Shetterly and Amanda Downum.
Bull graduated from Beloit College in 1976. Bull and Shetterly live in Arizona.