The Encyclopedia of Science Fiction (SFE) is an English language reference work on science fiction, first published in 1979. It has won the Hugo, Locus and British SF Awards. Two print editions appeared in 1979 and 1993. A third, continuously revised, edition was published online from 2011; a change of web host was announced as the launch of a fourth edition in 2021.

Peter Douglas Nicholls was an Australian literary scholar and critic. He was the creator and a co-editor of The Encyclopedia of Science Fiction with John Clute.