Synthajoy is a science fiction novel by D. G. Compton originally published in 1968 as an Ace Science Fiction Special in the United States and in hardcover by Hodder & Stoughton in Great Britain.

[1] The novel explores the social consequences of the development of a "virtual reality" technology "which enable[s] unremarkable people to enjoy the experiences of those who are more gifted or fortunate".

The protagonist is the wife of the creator of Synthajoy, who - realizing what damage it would do to society - murdered her husband, and was committed to a mental hospital.

[2] In a 2007 interview, Compton recalled that it was likely based "on the sort of popular science stuff that I as a non-scientist would have picked up out of the media or the general press and latched onto as something I could develop".

[3] James Blish wrote that "[N]obody has handled [the novel's theme] a tenth as well as this English writer.