Books about Human-alien encounters -- Fiction (sorted alphabetically)
- mystery of Deneb IV Robert Silverberg
- Native Soil Alan Edward Nourse
- Naudsonce H. Beam Piper
- Needler Randall Garrett
- Never Trust a Thief! Robert Silverberg
- Next Time We Die Robert Moore Williams
- night of no moon H. B. Fyfe
- Nobody saw the ship Murray Leinster
- No Sons Left to Die! Hal Annas
- Not Fit for Children Evelyn E. Smith
- Not in the Script Arnold Marmor
- Not Snow Nor Rain Miriam Allen De Ford
- Oh Mesmerist From Mimas! Roger D. Aycock
- Once a Greech Evelyn E. Smith
- Onslaught from Rigel Fletcher Pratt
- Open Invitation H. B. Fyfe
- Operation Terror Murray Leinster
- ordeal of Lancelot Biggs Nelson S. Bond
- Out of Mind William W. Stuart
- Outpost on Io Leigh Brackett
- overlord's thumb Robert Silverberg
- Pacifists Charles E. Fritch
- passionate pitchman Stephen Marlowe
- Pattern Robert H. Rohrer
- Peace Norman Arkawy and Stanley Henig