The Overseer
Albert E. Cowdrey
Over Yonder
Lucius Shepard
Outpost of Empire
Poul Anderson
Dominic Flandry (1)
Outnumbering the Dead
Frederik Pohl
Out of Time
James P. Hogan
Our Lady of American Sorrows
Jay Lake
The Other Side of Midnight
Kim Newman
Anno Dracula (1)
The Originist
Orson Scott Card
Foundation (5.5)
Originally Human
Eileen Wilks
The World of the Lupi (1)
Oracle
Greg Egan
An Opportunity for Profit
Dave Gross
Forgotten Realms: Double Diamond Triangle (5)
Operator "B"
Edward Lee
Open Your Eyes
Paul Jessup
The Only Neat Thing to Do
James Tiptree, Jr.
Rift (1)
Only Human
One of Her Paths
Ian Watson
Once Upon a Time in the North
Philip Pullman
His Dark Materials (1)
Once There Was a Giant
Keith Laumer