William Sleator, American author and composer (d. 2011)
William Warner Sleator III (February 13, 1945 – August 3, 2011), known as William Sleator, was an American science fiction author who wrote primarily young adult novels but also wrote for younger readers. His books typically deal with adolescents coming across a peculiar phenomenon related to an element of theoretical science, then trying to deal with the situation. The theme of family relationships, especially between siblings, is frequently intertwined with the science fiction plotline.

Due to the suspenseful and often eerie nature of some of his works, Sleator has been compared to young-adult horror writer R. L. Stine (who has identified himself as a fan of Sleator's work). Others cite a strong resemblance to the paranoid, dream-like style of Franz Kafka, which is most notable in House of Stairs, one of Sleator's more popular novels.