CNJ can refer to:
- The National Justice Council of Brazil
- Central Railroad of New Jersey
- Central Railroad of New Jersey 113
- The College of New Jersey, commonly abbreviated as TCNJ or CNJ.
- Camden New Journal, a free newspaper in the London Borough of Camden
- Chick'n Joy, a fastfood restaurant
- Chun Nan Jun, a Chinese auto manufacturer
- Cloncurry Airport, IATA airport code "CNJ"