He was a gifted pianist and composer who studied at Harvard University in Cambridge, Massachusetts but he switched his major to English. He later studied composition in London, England and worked as accompanist for the Royal Ballet School. He spent a decade as a pianist with the Boston Ballet before becoming a full-time writer.
His longtime companion Paul Peter Rhode died in 1999. His later companion of many years, Siang Chitsa-Ard died in 2008. His sister, Lucy Victoria Sleator Ward, died in 2003.
He is survived by his 2 brothers, Daniel Sleator, a computer scientist at Carnegie Mellon University in Pittsburgh, Pennsylvania and a brother Tycho Sleator, a physicist at New York University in New York City.
He was raised in University City, Missouri. Son of William Warner Sleator II, a physiologist, and Esther Kaplan Sleator, pediatrician.