- Omega Shadows
- Omega's Choice
- Omega's Onslaught
- Omega. I fuochi della guerra
- Omega. L'armata dei ribelli
- Omega: La fine è solo il principio
- Omega: Momenti perduti
- Omega: The Last days of the World
- Omelas Revisited
- Omens
- Omens and Artifacts: Elemental Legacy #.75
- Omens and Oracles and Eros, Oh My [a Diz & Dee mystery]
- Omens of Kregen [Dray Prescot #36]
- Omensent Dragons Falling
- Omensent: Birth of a Dragon Lord
- Omensent: Princess of Dragons
- Omensent: Revealing the Dragon
- Omensent: Rise of the Shadow Dragons
- Omensent: Son of the Dragon Lord
- Omensent: Wrath of a Dragon God
- Omicidi Alieni
- Omicidio nel Jet Set
- Omid's Story
- Omie 17
- Omina-Uvorix: The Legend
- Ominous Wave
- Ominous Winter
- Omission
- OMMYA - Die Gesamtausgabe der Fantasy-Serie mit den Romanen "1000 Welten", "Sechs Siegel" und "Armag...
- OMMYA - Freund und Feind
- Omnes Videntes
- Omni-One
- Omnia
- Omnia and the Fallen Kingdom Vol1
- OMNIA: Les Frontières Du Possible
- Omniadoodle
- Omnibus La Voie de l'Eldar
- Omnibus of Shadows
- Omnidirectional
- Omnifix
- Omnigalactic: The Eye of Shen'roth
- Omnigalactic: The Fangs of Z'et
- Omnihumans: Within A Concrete Labyrinth
- Omnihumans: Within A Concrete Labyrinth
- OMNILAND
- Omnimax II
- Omniphage Invasion
- Omnipotent Blood
- Omnipresence
- Omnipresent Occultation
- Omnis, an Everlasting Birth
- Omniscience Among Mortals
- Omnitempus / The Quenar Affair
- Omniverse: Book I of the Omniverse Chronicles
- OmniWar: Anunnakx
- OmniWar: Horsemen
- OmniWar: Omicron
- Omorti's Legacy: Book Three
- Omphale
- Omstart
- Omul focului
- Omvänd (Bok #1 i Vampyrjournalerna)
- Oméga
- OM—The Secret of Ahbor Valley
- On
- On 20468 Petercook
- On a Black Horse: Book 1 of the Devil’s Bible Series
- On a Clear Winter Night: An Irin Chronicles Novelette
- On A Cold Wind
- On a Crooked Track
- On a Dark Road to Nowhere
- On A Fooler's Errand
- On a Forsaken Land Found
- On A Journey To Mirth
- On a little street in Singapore
- On a Long Forgotten Road: anno nil - year zero
- On A Pale Horse
- On a Red Station, Drifting
- On a Torn-Away World
- On a Witch's Mind
- On Account of Darkness
- On an Odd Note
- On Angel's Wings
- On Angelic Wings
- On Armored Wings
- On Astronaut Wings
- On Basilisk Station
- On Becoming Master of Time and Space
- On Behalf of the Widow
- On Black Mesa
- On Blackened Wings
- On Bliss
- On Blue's Waters
- On Bullies & Gods
- On Celestra’s Wings
- On Cloud Nine
- On Common Ground
- On Demon Wings
- On Distant Shores (Earth Exiles, Book 1)
- On Distant Worlds: The Prologues & Colibri
- On Dragons Wings: A Trio of Tales from the Land of Druimoor
- On Dragons' Wings
- On Dreaded Wings: An Urban Fae Charity Anthology
- On Duty
- On Eagles Wings
- On Earth, As It Is: A Kingdom Fantasy Novel
- On Edge
- On Fire
- On Gryphon's Wings
- On Guard (The Eternal Dungeon, Volume 4)
- On Hallow's Eve
- On Handling the Data
- On Heroes
- On Heroes: A Foible
- On His Birthday, Reginald Got
- On Holiday with an S.O.B.
- On Hostile Ground
- On Ice
- On Ice '93
- On Jericho Flats
- On Loan: A Reading Under Wraps Short Story
- On Love's Edge
- On Midnight Wings
- On Moonlit Wings
- On My Father's Bike
- On My Terms
- On My Way