Books about Human-alien encounters -- Fiction (sorted alphabetically)
- Way Back Sam Moskowitz
- way out Richard Rein Smith
- Weapon Jesse F. Bone
- Weather on Mercury Joseph Samachson
- Weirdest World R. A. Lafferty
- We're Civilized! Mark Clifton and Alex Apostolides
- What Inhabits Me? Robert Moore Williams
- What's He Doing in There? Fritz Leiber
- When the atoms failed Jr. John W. Campbell
- When Whirlybirds Call Frank Banta
- White spot Murray Leinster
- Who Goes There? Charles H. Davis
- Winds of Time James H. Schmitz
- Woman from another planet Frank Belknap Long
- Woman's touch Evelyn E. Smith
- World in a Mirror Albert Teichner
- World of Mockery Sam Moskowitz
- World That Couldn't Be Clifford D. Simak
- world to die for Sam Carson
- Xipéhuz (French) aîné J.-H. Rosny and jeune J.-H. Rosny
- You Don't Walk Alone Frank M. Robinson
- Youth Isaac Asimov
- Zero Hour Ray Bradbury
- Zloor for Your Trouble! Mack Reynolds