William Sleator (1945–2011) was an American science fiction author best known for his young adult novels. Raised outside of St. Louis, Missouri, Sleator was the eldest of four children. After graduating from Harvard University with a degree in English, he moved to England for a short time, where he played music for ballet classes and developed the ideas for Blackbriar, his first novel. For many years, he was the rehearsal pianist for the Boston Ballet.
Sleator is the author of over thirty books, including The Angry Moon, which was awarded the Caldecott Medal and nominated for the National Book Award, as well as the quasi-autobiographical science fiction thrillers: The Night the Heads Came, Others See Us, and Oddballs. In his later years, he split his time between Boston and rural Thailand.