Japp may refer to:
- Alexander Hay Japp (1837–1905), Scottish author, journalist and publisher
- Francis Robert Japp, British chemist
- Mikel Japp, Welsh musician
- Chief Inspector Japp, a fictional police officer created by crime writer Agatha Christie
- Japp, a chocolate bar produced, marketed and sold by Marabou in Sweden and Freia in Norway.
- Journal of Adolescent Psychology and Psychiatry