- Open Minds
- OPEN SESAME Volume 1
- OPEN SESAME Volume 2
- OPEN SESAME Volume 3
- OPEN SESAME Volume 4
- OPEN SESAME Volume 5
- Open Thy Heart
- Open Werther
- Opening
- Openly Straight
- Openly, Honestly
- Operación Ancla
- Operación Ave
- Operación Beowulf
- Operación cliché
- Operación Demonio
- Operación Escudo
- Operación Pelusa
- Operación San Valentín
- Operación ¡a la cama!
- Operación Águila
- Operacja Dexter
- Operas That Every Child Should Know
- Operatic Duck / Duck On Tour
- Operatie Groene Erwt
- Operatie Nieuwsflits
- Operatie Noorderlicht
- Operatie Zeer Ernstige Ramp
- Operation Absolution
- Operation Beautiful
- Operation Cat Tale
- Operation Clean Sweep
- Operation Do-Over
- Operation Eiffel Tower
- Operation Falkenstein und die Angst vor dem Unbekannten
- Operation Frog Effect
- Operation Gemsbok
- Operation Glücksstern
- Operation Homecoming Queen
- Operation Ice Maker
- Operation Josh Taylor
- Operation Marriage
- Operation Normal
- Operation Prom Date
- Operation Pucker Up
- Operation Red
- Operation S.O.S.
- Operation Sasquatch
- Operation Skæbnespil
- Operation Stargazer
- Operation Stay in England
- Operation: Blueberry Pancake
- Operation: Containment
- Operation: Dump the Chump
- Operation: Montauk
- Operation: Save Halloween
- Operation: Save Santa
- Operation: Survival
- Operazione controspionaggio
- Operazione Cristopher
- Operazione N.O.N.N.O.
- Operazione tigre volante
- Operação Cambess
- Operculum
- Opere. Viaggio notturno. Mozart. La conversione di Ratisbonne (con note e espansione online)
- Opferland
- Opfør dig ordentligt, og vær en god ven
- Opgejaagd
- Opgepast!
- Opgøret
- Ophelia After All
- Ophelia and the Marvelous Boy
- Ophelia Scale - Der Himmel wird beben
- Ophelia Scale - Die Sterne werden fallen
- Ophelia Scale - Die Welt wird brennen
- Ophelia Scale - Wie alles begann
- Ophie's Ghosts
- Opie Jones and the Superhero Slug
- Opie Jones Talks to Animals
- Opopomoz
- Opostos
- Opowiadania dla przedszkolaków
- Opowiastki świąteczne
- Opowieści niezwykłe
- Opowieści o małej czarownicy Ismie
- Opowieści o uczuciach
- Opowieści wigilijne 2. Świerszcz za kominem
- Opowieść wigilijna
- Oppassen
- Oppdrag abort
- OPPORTUNELLA
- Opposing Sides
- Opposite Island
- Opposite of Always
- Oppositecy Prophecy
- Opposition (Lux - Book Five)
- Oppositecy Prophecy
- Opposition (Lux - Book Five)
- Opposition (Saga LUX 5)
- Oppressed An Arelia LaRue Novel #4
- Oprøret i Budapest
- Opstand
- Opstandeling, Pion, Koning (Over Kronen en Glorie—Boek 4)
- Optifly et l'optimisme 04
- Option Four
- OPUS - Das verbotene Buch
- OPUS - Die Bücherjäger
- Opus Gemini III
- Opus Poemador
- Opération "Maurice"
- Opération au lit!
- Opération Beurre de Pinottes
- Opération casse-croûte
- Opération Dreamteam
- Opération Jehanne d'Arc
- Opération Léviathan
- Opération Manchots - Lecture roman jeunesse aventure écologie animaux - Dès 9 ans
- Opération Pantalon
- Opération Phantom
- Opération Tempête de Sable
- Opération tombeau d'Achille
- Opération vide-grenier - Ebook
- Opération Vox
- Opętana (Część 12 Wampirzych Dzienników)
- Or the Girl Dies
- Ora di crescere
- Ora esisti solo tu
- Ora lo sai
- Oracle In The Mist
- Oracle of Doom (The Library Book 3)
- Oracles of Delphi Keep
- Oracles' Tale
- Orage assassin
- Orage sur le Val d'Hespar
- Orage, petit seigneur des ténèbres - Lecture roman jeunesse conte - Dès 8 ans
- Orages
- Oraklets gåta
- Oran 62 : La rupture
- Orang Ketiga
- Orange Animals On The Planet
- Orange Crush
- Orange Fairytales
- Orange Fish, Green Fish