Nox may refer to:
- Nox (mythology), the Roman translation of Nyx, the primordial god of the night in Greek mythology.
- Nox (video game), a video game developed by Westwood Studios
- Nox (band), a pop band from Hungary
- Nox, Shropshire, a place in Shropshire, England
In fiction
- Nox (Stargate), a race in the television series Stargate SG-1
- Nox (Marvel Comics), a fictional character appearing in the Marvel Comics universe, based loosely on Nyx of Greek mythology
- Nox, a spell in the Harry Potter books
- The chief antagonist of the Wakfu cartoon series, Noximilien, better known as Nox.
In science
- nox (nx), a unit of illuminance, equal to 1/1000 lux
- NOx, a term for the nitrogen oxide air pollutants NO and NO2
- Nox2, a subunit of NADPH oxidase
- Species group of butterfly genus Atrophaneura