Books in Science Fiction (sorted alphabetically)
- Impact Irving E. Cox
- Impossibles Randall Garrett and Laurence M. Janifer
- In Case of Fire Randall Garrett
- Incident on Route 12 James H. Schmitz
- Indirection Everett B. Cole
- Indulgence of Negu Mah Robert Arthur
- Industrial Revolution Poul Anderson
- Infra-Medians Sewell Peaslee Wright
- Innocent at Large Poul Anderson and Karen Anderson
- In Search of the Unknown Robert W. Chambers
- Inside Earth Poul Anderson
- Inside John Barth William W. Stuart
- Insidekick Jesse F. Bone
- Instant of Decision Randall Garrett
- Instant of Now Irving E. Cox
- Instinct George O. Smith
- In the Control Tower Will Mohler
- In the Orbit of Saturn Roman Frederick Starzl
- In the year 2889 Jules Verne and Michel Verne
- Invader Alfred Coppel
- Invaders Benjamin Ferris
- Invaders from the Infinite Jr. John W. Campbell
- Invasion Murray Leinster
- Irresistible Weapon H. B. Fyfe
- island of Doctor Moreau H. G. Wells