Jacek Józef Dukaj is a Polish science fiction and fantasy writer. His fiction explores such themes as alternate history, alternative physics and logic, human nature, religion, the relationship between science and power, technological singularity, artificial intelligence, and transhumanism. He is regarded among the most popular Polish contemporary science fiction authors.

The Janusz A. Zajdel Award, often called just Zajdel, is the annual award given by the Polish science fiction and fantasy fandom for the best stories published in the previous year.