Books about Human-alien encounters -- Fiction (sorted alphabetically)
- Ultimate Eve H. Sanford Effron
- Ultimatum Roger D. Aycock
- Under the Skin Leslie Perri
- Uniform of a Man Dave Dryfoos
- universe wreckers Edmond Hamilton
- Unprotected Species Melvin Sturgis
- untouchable adolescents Harlan Ellison
- Unwelcomed Visitor Joseph Samachson
- Unwilling Professor Arthur Porges
- Useless Bugbreeders James Stamers
- Vandals of the Void Robert Wilson
- vanguard of Venus Landell Bartlett
- Vanisher Michael Shaara
- Vanishing Venusians Leigh Brackett
- Vegans Were Curious Winston K. Marks
- Venus Enslaved Manly Wade Wellman
- Venus Evil Chester S. Geier
- Venus Trap Evelyn E. Smith
- Very Secret Agent Mari Wolf
- Vibration Wasps Frank Belknap Long
- Victory of Klon Wilbur S. Peacock
- Vocation George O. Smith
- voice of the void Jr. John W. Campbell
- War-Gods of the Void Henry Kuttner
- Watchers Roger D. Aycock