- O Caso Do Assassino Das Páginas
- O is for Outlaw
- O jogo Suicida
- O'Casey's War
- Oakland Noir
- Oben in den Ruinen liegt ein Mann erschlagen
- Obras Maestras de H.P. Lovecraft
- Obsession
- Obsession in Death
- Occupational Hazards
- October Fury
- Odeur de sang à Penvénan
- Odio en las manos
- Off the Beaten Path
- Ofiary
- Ogni uomo uccide ciò che ama
- Oh Clarence
- Ohnmachtspiele
- Oiseau de nuit
- Okergeschichten - Verbrechen. Wahnsinn. Leidenschaft.
- Okkult Krimi Sammelband: Die komplette Finn Steinmann Serie
- Old Mother Curridge
- Old Tin Sorrows
- Old Wounds, a Gino Cataldi Mystery
- Ole dole död
- Oltre la giustizia
- Oléron couleurs pourpres
- Omand's Creek
- Ombre givrée
- Omicidio a Santa Gilla
- Omicidio dietro le quinte
- Omicidio in Piazza Sant'Elena
- On a Lonely Path
- On the Line
- On the Run
- On The Run
- On the Street Where You Die
- On the Streets for Alison
- On the Streets for Coleman
- On the Streets for Eva
- On the Streets for McKaylah
- On-line
- Once Darkness Falls
- Once Were Cops
- Once You Go This Far
- Onde spil
- Ondijk/Punt
- Ondskab
- One
- One Bright Summer Morning
- One Child Alive
- One Dark Night
- One Drop Blood
- One Endless Hour
- One Foot Off the Gutter
- One Good Deed
- One Hour
- One Hour Late
- One Is A Lonely Number
- One Last Kill
- One Lonely Night
- One Man Two Votes
- One Monday We Killed Them All
- One More Body
- One More Sunday
- One More Way to Die
- One Night
- One Night with Nora
- One Oblique One
- One Per Coffin
- One Police Plaza
- One to Watch
- One True Love
- One Under
- One-Shot Deal
- Only Child
- Only Dangerous In The Breeding Season
- Only Darkness
- Only in L.A.
- Opdracht voor een snuffelaar
- Operation Archimedes
- Operation Black Key
- Operation Archimedes
- Operation Black Key
- Operation Chess
- Operation Red Alert: The Iron Eagle Series Book Four
- Operation: Refugees DEADcome
- Opfere dich
- Opgave til en snushane
- Opération Kipling
- Opération Petrouchka
- Opération vent d’Ouest dans le Trégor
- Orange Crush
- Oranges amères
- Ordeal by Innocence
- Ordinary Mayhem
- Ordonnance tragique à Binic
- Origin In Death
- Ormguden
- Os Imperios de Vidro: As Aventuras de Brouder, O Rei Corvo
- Os mortos inocentes
- Ossa dimenticate
- Other People's Money
- Other People’s Money
- Otoño lejos del nido
- Oubli interdit
- Our Dangerous Lies
- Our Fathers: Book 1 In the Connor Beach Crime Series
- Our Little Cruelties
- Ouragan sur Damgan
- Ouragan sur le Cairn
- Ouroboros
- Out for Blond
- Out of Mind
- Out On The Cutting Edge
- Out on the Cutting Edge
- Out There Bad
- Outlawed Ink
- Outrages
- Outside Looking In (DCI Matilda Darke, Book 2)
- Outside The Box
- Outside the Line