Ideomancer is an online speculative fiction magazine which specialises in publishing science fiction, fantasy, slipstream, horror short stories and flash fiction, along with speculative poetry, reviews and interviews.
The first issue was published in 1999 under the joint editorship of Chris Clarke and Mikal Trimm, with Clarke overseeing the publishing of the magazine from Perth, Western Australia. The members of the editing team were based in Canada, Ireland and the USA.
In 2002 Clarke and Trimm edited an ebook anthology called Ideomancer Unbound published by Fictionwise. That same year the magazine was "rebooted" by a new publisher and editor, Leah Bobit. The changes included a new numbering system and new editorial staff.