Since he first came to prominence in the mid-1960s, critics have cited Campbell as one of the leading writers in his field: T. E. D. Klein has written that "Campbell reigns supreme in the field today, while S. T. Joshi stated, "future generations will regard him as the leading horror writer of our generation, every bit the equal of Lovecraft or Blackwood.
His early work was greatly influenced by the work of H. P. Lovecraft. His first collection, The Inhabitant of the Lake and Less Welcome Tenants, is a volume of Cthulhu Mythos stories published by Arkham House in 1964. At the suggestion of August Derleth, he rewrote many of his earliest stories, which he had originally set in the Massachusetts locales of Arkham, Dunwich and Innsmouth, and relocated them to English settings in and around the fictional Gloucestershire city of Brichester, near the River Severn, creating his own Severn Valley milieu for Lovecraftian horrors. Brichester was deeply influenced by Campbell's native Liverpool, and much of his later work is set in the real locales of Liverpool and Merseyside. In particular, his 2006 novel Secret Stories (published in the U.S. as Secret Story) both exemplifies and satirizes Liverpudlian speech, characters, humor, and culture. Having spent a number of months working full-time in a Borders store, he wrote The Overnight (2004), about bookshop staff trapped in their hellish workplace during an overnight shelf-filling shift.
With the collection Demons by Daylight (1973), Campbell set out to be as unlike Lovecraft as possible. In 1969, he had written "Lovecraft in Retrospect", an essay for the fanzine Shadow, "condemning [Lovecraft's] work outright. However, in his 1985 book Cold Print, which collects his Lovecraftian stories, Campbell disavowed the opinions expressed in the article, stating: "I believe Lovecraft is one of the most important writers in the field and "the first book of Lovecraft's I read made me into a writer. Demons by Daylight includes "The Franklyn Paragraphs", which uses Lovecraft's documentary narrative technique without slipping into parody of his writing style. Other tales, such as "The End of a Summer's Day" and "Concussion", show the emergence of Campbell's highly distinctive mature style, of which S. T. Joshi has written:
Certainly much of the power of his work derives purely from his prose style, one of the most fluid, dense and evocative in all modern literature.... His eye for the details and resonances of even the most mundane objects, and his ability to express them crisply and almost prose-poetically, give to his work at once a clarity and a dreamlike nebulousness that is difficult to describe but easy to sense.Subsequently, Campbell has published a number of other collections; many of his most popular stories can be found in the 1993 collection Alone with the Horrors.
Campbell has written many novels, both supernatural and non-supernatural. They include The Face That Must Die (cut by the publisher on its first release in 1979 and issued complete in 1983), the story of a homophobic serial killer told largely from the killer's point of view. A more sympathetic serial murderer appears in the later novel The Count of Eleven (1991), which displays Campbell's gift for word play, and which the author has said is disturbing "because it doesn't stop being funny when you think it should". Other non-supernatural novels, such as The One Safe Place (1995), use a highly charged thriller narrative to examine social problems such as the deprivation and abuse of children.
Campbell's supernatural horror novels include Incarnate (1983), in which the boundaries between dream and reality are gradually broken down; and Midnight Sun (1990), in which an alien entity apparently seeks entry to the world through the mind of a children's writer. In its fusion of horror with awe, Midnight Sun shows the influence of Algernon Blackwood and Arthur Machen as well as Lovecraft. Also notable is the novella Needing Ghosts, a nightmarish work that blends the horrific and the comic.
Outside the world of horror, he has written a series of fantasy stories starring Ryre the Swordsman, an original creation. Many of these stories were published in the collection Far Away & Never. In 1976 he "completed" three of Robert E. Howard's unfinished Solomon Kane stories, "Hawk of Basti", "The Castle of the Devil" and "The Children of Asshur". He has also written a few works of science fiction, such as the novella Medusa (1973) and the short story "Slow" (collected in Told by the Dead), but has stated that his science fiction "tried to deal with Themes, too consciously, I feel".
Campbell has also edited a number of anthologies, including New Tales of the Cthulhu Mythos (1980), New Terrors (1980) and (with Stephen Jones) the first five volumes of the annual Best New Horror series (1990-1994). His 1992 anthology Uncanny Banquet was notable for including the first ever reprint of the obscure 1914 horror novel The Hole of the Pit by Adrian Ross.
Ramsey Campbell, Probably, a collection of Campbell's book reviews, film reviews, autobiographical writings and other nonfiction, was published in 2002. The book included reminiscences and appreciations of authors such as John Brunner, Bob Shaw and K. W. Jeter and an extensive, negative critique of Shaun Hutson's Heathen, parodying Hutson's style.
He married Jenny Chandler, daughter of A. Bertram Chandler, on 1 January 1971; has two children, Tamsin (born 1978) and Matthew (born 1981); and still lives on Merseyside. A lifelong enthusiast of film (old movies feature prominently in two of his novels, Ancient Images and The Grin of the Dark), he reviewed films and DVDs weekly for BBC Radio Merseyside until 2007. He writes a monthly film column, "Ramsey´s Ramblings", for Video Watchdog magazine.
He is the Lifetime President of the British Fantasy Society.
Gary William Crawford's reader's guide to Campbell, Ramsey Campbell (1988), provides an overview of his work up to 1987. There is an extensive critical analysis of Campbell's work in S. T. Joshi's book The Modern Weird Tale (2001). Joshi has also written a book-length study, Ramsey Campbell and Modern Horror Fiction (2001), and edited The Count of Thirty (Necronomicon Press 1994), which contains critical appreciations by various authors and a long interview with Campbell himself.