Out of House and Home
Drew Hayes
Fred, the Vampire Accountant (7)
Home, Siege Home
Eric Ugland
The Good Guys (6)
Eye Spy
Mercedes Lackey
Valdemar (Chronological) (19)
The Amazing Maurice and His Educated Rodents
Terry Pratchett
Discworld (28)
Outcasts of Order
L.E. Modesitt Jr.
The Saga of Recluce (19)
Otherness
David Brin
The Other
K.A. Applegate
Animorphs (40)
Orphan Star
Alan Dean Foster
Pip & Flinx (3)
Ordermaster
The Saga of Recluce (13)
The Order War
The Saga of Recluce (4)
The ordeal of the haunted room
Jodi Taylor
The Chronicles of St Mary's (11.5)
Orconomics
J. Zachary Pike
The Dark Profit Saga (1)
Open Sesame
Tom Holt
The Opal Deception
Eoin Colfer
Artemis Fowl (4)
Only You Can Save Mankind
Johnny Maxwell (1)
Only Superhuman
Christopher L. Bennett
One-Armed Beasthunter 2
E.M. Hardy
Aberrant Farmer (2)
One-Armed Beasthunter
One of Our Thursdays Is Missing
Jasper Fforde
Thursday Next (6)
One More Last Time
The Good Guys (1)
On a Throne of Lies
The Bad Guys (10)
Off to Be the wizard
Scott Meyer
Magic 2.0 (1)
Of Myths and Legends
Michael Chatfield
Emerilia (9)
Obligations Incurred
Blaise Corvin
Delvers LLC (2)
Oathbringer
Brandon Sanderson
The Stormlight Archive (3)
Oathbreakers
Valdemar: Vows and Honor (2)
Oathblood
Valdemar: Vows and Honor (3)
NPCs
Spells, Swords, & Stealth (1)