John Clute, the Critic Guest of Honor at Readercon 4, was born in Canada in 1940, and has lived in England since 1969 in the same Camden Town flat; since 1997, he has visited America yearly, spending much of his time with Elizabeth Hand in Maine. He received a Pilgrim Award from the SFRA in 1994, and was Distinguished Guest Scholar at the 1999 International Conference for the Fantastic in the Arts.

He was Associate Editor of the Hugo-winning first edition (Doubleday, 1979) of the Encyclopedia of Science Fiction, general editor Peter Nicholls; with Nicholls, and co-edited the second edition (St. Martin's, 1993), which won the British Science Fiction Special Award, the Locus Award, the Hugo, and the Eaton Grand Master Award. With John Grant, he co-edited the Encyclopedia of Fantasy (St. Martin's, 1997), which won the Locus Award, the Hugo, the World Fantasy Award, the Mythopoeic Society Award, and the Eaton Award. Solo, he wrote Science Fiction: The Illustrated Encyclopedia (Dorling Kindersley, 1995) (Locus Award, Hugo), which is actually a companion, not an encyclopedia. The Book of End Times: Grappling with the Millennium appeared in 1999.

Book reviews and other criticism have been assembled in Strokes: Essays and Reviews 1966 - 1986 (Serconia, 1988; Readercon Award); in Look at the Evidence: Essays and Reviews (Serconia, 1996; Locus Award); in Scores: Reviews 1993 - 2003 (Beccon, 2003) and in Canary Fever: Reviews (Beccon, 2009). The Darkening Garden: A Short Lexicon of Horror (Payseur & Schmidt, 2006) argues that horror is central to 21st century fantastika; some of the pieces assembled in Pardon This Intrusion: Fantastika in the World Storm (Beccon, 2011) further this argument. He has published two novels: The Disinheriting Party (Allison and Busby, 1977) and Appleseed (Orbit/Little Brown, 2001; Tor, 2002), which was a New York Times notable book for 2002.

Projects include a third edition of the Encyclopedia of SF, co-written and -edited with David Langford and Peter Nicholls (Editor Emeritus), a beta version now being due for online release at the end of 2011.