Originally established in 1979 by Philip Harbottle, Cosmos Books was later revived by the partnership of Harbottle and Sean Wallace. It quickly published four trade paperback books within a year, including E.C. Tubb's Death God's Doom, its sequel The Sleeping City, John Russell Fearn's Manton's World, and the third issue of Fantasy Annual.

The title license to Cosmos Books was then acquired by John Gregory Betancourt of Wildside Press in July of 1999. Since then we're released over a hundred titles, spanning science fiction, fantasy, and horror.
- Sean Wallace