Nameless: a private eye in San Francisco, California by Bill Pronzini

Narrabone, Joe: a WWI policeman turned British Secret agent in London, England by Michael Gilbert

Nautilus, Harry: a police detective in Alabama by Jack Kerley

Navarre, Jackson “Tres”: Tai Chi master, unlicensed P.I. in San Antonio, Texas by Rick Riordan

Nebraska: part-time PI trying to write in Omaha, Nebraska by William J. Reynolds

Nelson, Vicki: an ex-cop turned private investigator with a vampire lover in Toronto, Ontario, Canada by Tanya Huff

Ness, Eliot: 1930s public safety officer in Cleveland, Ohio by Max Allan Collins

Nestleton, Alice: actress and cat-sitter in New York, New York by Lydia Adamson

Newcomb, Chloe: victims advocate in Cochise County, Arizona by Beth Thornton

Newman, Bob: a British secret agent written as by Corbin Forbes

Newman, Terrell: a detective in San Antonio, Texas by Bernard J. Taylor

newsroom crew: in Minneapolis, Minnesota by Ron Handberg

Nez, Lee: a nightwalker (vampire) police officer in New Mexico by Aimee and David Thurlo

Nichols, Jane: secret agent turned mystery writer in Savannah, Georgia by Maureen Tan

Nickerson, Martha "Marty": a prosecuting attorney of Chatham on Cape Cod, Massachusetts by Rose Connors

Nightingale, Deirdre Quinn: veterinarian in New York, New York by Lydia Adamson

Nilsen, Pam: lesbian printing company owner in Seattle, Washington by Barbara Wilson

Noble, Charlie: ex-Coast Guard officer turned marine private investigator by Clyde W. Ford

Nobel, Parker: a deputy attorney general and burned-out former prosecutor by Mike Manno

Nolan: aging thief in Iowa by Max Allan Collins

Norgren, Chris: art museum curator in Seattle, Washington by Aaron Elkins

North, Eddie: a police sergeant in Philadelphia, Pennsylvania by Scott Flander

North, Tru: a lesbian police detective in Kansas City, Missouri Janet McClellan

Norton, Les: a nightclub bouncer in Sydney, Australia by Robert G. Barrett

Nudger, Alo: a private investigator in St. Louis, Missouri by John Lutz