Encyclopedias, Almanacs, Transcripts, and Maps
- Nicole d'Oresme
- Nicole-Reine Lepaute
- Nicoll, (Henry) Maurice (Dunlap)(1884-1953)
- Nicomedes
- Nictalopes
- Niels Ryberg Finsen
- Nielsen, Einer (d. 1965)
- Nielsen, Winnifred Moon (1917-)
- Nielsson, Haraldur (d. 1928)
- Nietzsche, Friedrich W.
- Nif
- Night Lizards: Xantusiidae
- Night Monkeys: Aotidae
- Night Vision Enhancement Devices
- Night Vision Enhancement Devices
- Nightjars: Caprimulgidae
- Nightjars: Caprimulgiformes
- Nijmegen breakage syndrome
- Nijmegen Breakage Syndrome
- Nikolai Ivanovich Lobachevsky