The abbreviation JN stands for:
- Jan Mayen, country code of the island after the " FIPS PUB 10-4 territory code"
- Johnson - Nyquist noise, caused by thermal motion of the charge carriers in electric circuits noise
- Young National Democrats, the youth organization of the extreme right party NPD
- Jurassic Neuchâtelois, a former railway company in Switzerland
- Jurisdiction Act, Austrian law governing the exercise of jurisdiction and the jurisdiction of the ordinary courts in civil law matters.
JN as distinguishing signs on license plate:
- Norway: Gjøvik in the province of Oppland
- Czech Republic: for Okres Jablonec nad Nisou, German: Jablonec nad Nisou ( discontinued)