JN may refer to:
- Jan Mayen: FIPS PUB 10-4 territory code
- Johnson–Nyquist noise (also thermal noise, Johnson noise or Nyquist noise), the noise generated by the random thermal motion of the electric current carriers inside an electrical conductor
- Jornal de Notícias, a Portuguese leading newspaper
- Jornal Nacional, a Brazilian news program
- Excel Airways IATA airline designator
Jn or Jn. may refer to:
- Gospel of John