AJP or ajp may refer to:

• American Journal of Philology, published by Johns Hopkins University Press
• American Journal of Psychiatry, published by the American Psychiatric Association
• American Journal of Psychology, published by the University of Illinois Press
• American Journal of Physics, published by the American Association of Physics Teachers and the American Institute of Physics
• American Journal of Physiology, published by the American Physiological Society
• Asian Jake Paul, single by American Youtuber IDubbbz
• Australasian Journal of Philosophy, published by the Australasian Association of Philosophy
• AJP Motos, a Portuguese motorcycle brand
• Animal Justice Party, a political party in Australia focusing on animal rights
• Apache JServ Protocol, protocol for computer servers
• All Japan Pro Wrestling, Japanese professional wrestling promotion
• South Levantine Arabic (deprecated ISO 639-3 code)
• AJP6 and AJP8, TVR engines
• Assam Jatiya Parishad, political party in India