The Chrysalids is a science fiction novel written by John Wyndham. While Wyndham wrote many science fiction novels and short stories, this work deviates from his oeuvre in many ways, as well as from most science fiction. Primarily, while the story is set in the future (as is typical of many science fiction works), it is a future in which people live an old-fashioned life. Three hundred years after a nuclear apocalypse, people are attempting to rebuild from what is left. While some civilizations that were far away from the attacks managed to build quickly and even thrive, others, particularly those in North America, were all but destroyed. What is left is largely a wasteland and a plague of radiation poisoning that never seems to go away.

Unlike most science fiction novels set in the future, the setting resembles the past. The people ride horses, use bows and arrows, and lack technology such as airplanes and cars. Similarly, while many science fiction plots rely on some scientific breakthrough, futuristic technology, or advancement, The Chrysalids examines what happens when a society turns its back on progress, both scientifically and socially. Within Waknuk, scientific advancement is absent, and the society is structured around a strict, oppressive religious doctrine.