Harper Prism (1993–1999) was launched by John Silbersack, Publishing Director, in 1993 as the first science fiction and fantasy imprint of HarperCollins Publishers in the United States.^[1] Prism's early authors included Stephen Baxter, Terry Pratchett, Isaac Asimov, and Clive Barker as well as many media and gaming tie-ins such as Magic: The Gathering and The X-Files.

When HarperCollins acquired Avon Books in 1999, the Harper Prism imprint was absorbed into the Avon Eos line.