Here are a dozen mystery and thriller publishers that don't require an agent. All are traditional publishers. (No vanity presses) Make sure your manuscript is complete before you submit. None of these publishers accept proposals or partially completed work.
Happy submitting!
_____________________
Camel Press is the genre imprint of Coffeetown Press. (Coffeetown Press publishes memoir, nonfiction, some literary mysteries, and literary fiction). "Camel Press is a feisty little publisher with a mission: to be your trusted purveyor of popular literature—the stuff that makes you lie in the sun too long and read in bed until the cock crows, the urban chickens start clucking, or your neighbor leaves for her 6 am shift." Seeking: Genre fiction: mystery/suspense, cozy mystery, mystery thrillers, romantic suspense and romance (contemporary and historical). They also consider general fiction, historical fiction and westerns. Read their guidelines here.
Crooked Lane publishes mysteries, thrillers, and suspense. titles in both print and electronic editions. Crooked Lane Books is distributed through Legato Publishers Group, a member of the Perseus Books Group. Crooked Lane is also represented by Biagi Literary Management for subsidiary rights licensing in foreign and domestic markets, and their business relationships include Bookspan, home of the country’s largest book clubs, and Blackstone Audio, one of the nation’s largest independent audiobook publishers. Read submission guidelines here.
Dark Edge Press is the crime imprint of Usk River Publishing (UK). They are a digital first publisher. Dark Edge accepts Psychological, Crime, Legal, Medical, Techno, and Hard-boiled Action-packed Thrillers. Procedurals, Chillers, Grip-lit, and Domestic noir. Read submission guidelines here.
Fahrenheit Press exclusively publishes mysteries and thrillers. They accept self-published and previously published work, provided the author has all the rights. They offer a generous royalty rate of 50% on both eBooks & paperback editions for a 5 year contract. Read submission guidelines here.
Felony and Mayhem was launched in 2005, and now has more than 100 titles in print. Their focus is on literary mystery fiction. "We love wit, we love elegance, we love distinctive narrative voices. And while we may sound a little snotty, the truth is that we would love nothing more than to find your witty, elegant, distinctive manuscript in our inbox." The minimum length is roughly 75,000 words. Read submission guidelines here.
Hard Case Crime publishes old-fashioned, hard-boiled crime novels with "bare-knuckled" prose. They are unabashedly dedicated to "reviving the vigor and excitement, the suspense and thrills—the sheer entertainment—of the golden age of paperback crime novels, both by bringing back into print the best work of the pulp era and by introducing readers to new work by some of today's most powerful writers and artists. Determined detectives and dangerous women...fortune hunters and vengeance seekers...ingenious criminals and men on the run..." Read submission guidelines here.
Joffe Books is one of the UK’s leading independent publishers of crime and mystery novels. Many of their authors have topped the best-seller lists. They accept submissions from published authors and new writers, as well as authors who wish to relaunch their back-list titles. They are seeking mysteries, crime fiction, psychological thrillers, detective, thrillers, and suspense. Read submission guidelines here.
Level Best, a publisher of anthologies, has recently opened its doors to full-length manuscript submissions. They are seeking crime fiction novels in the following categories: mystery, thriller, suspense, historical, traditional, and contemporary. No works of erotica or science fiction at this time. Read submission guidelines here.
Lyrical Press, an imprint of Kensington, publishes suspense fiction, thrillers, and cozy mysteries. They have a penchant for romance. Submit to one editor only. (The list of editors includes the genres they are receiving.) Response time is three months. Read submission guidelines here.
Oceanview Press is an independent publisher of original mystery, thriller, and suspense titles. Oceanview Publishing’s titles have received many awards and award nominations. Read submission guidelines here.
Seventh Street Books--where fiction is a crime—is devoted to publishing quality mystery, thriller, and crime fiction. It is an imprint of Prometheus Books, an independent publisher of progressive nonfiction. A number of their debut titles have won prestigious awards, including the Edgar Award, the Mary Higgins Clark Award, and the Anthony Award. Read submission guidelines here.
Tule Publishing specializes in romance and mystery ebooks. In mysteries they are looking for Domestic suspense, Cozy mysteries, Private Investigators, Mystery stories with diverse characters, Detective mysteries with women sleuths, Police Procedural, Thrillers. Read submission guidelines here.