KJ or kJ is an acronym that could be referring to:

• K. J. Yesudas, A famous musician/singer from Kerala, India
• K-J a.k.a Kureen J. Cook [Fresno Underground Rap Legend] Member of Noo Tribe Records/Greedy Green Records Kingpins Only and Virgin Records/A.W.O.L Records group Dosia album "Waiting To Inhale" with Killa Tay and Luni Coleone. Featured on Bullys Wit Fully's with Killa Tay and Guce, Killa Tay's albums "Snake Eye's" along with EDI from the Outlaws, Yukmouth, C-Bo, Marvaless, Tupac's sister Set Shakur and Brotha Lynch, Mr. Mafioso and Thug Thizzle along with Spice 1, Bad Ass of Dogg Pound, King Tee and Tupac's Outlaw's", Luni Coleone's albums "Total Recall and Million Words a Million Dollars", Cold World Hustlers "Anything for Money".
• KJ is the model code of the Jeep Liberty
• kilojoule (kJ), an SI unit of energy equal to 10³ joules
• Khairy Jamaluddin, Malaysian politician
• British Mediterranean Airways IATA airline designator
• Kaisertreue Jugend, a German monarchist organization
• Kevin Johnson nickname, former NBA player
• Karaoke jockey, a disc jockey that specializes in running karaoke events
• Kay-Jay Harris, American football player
• K. J. Hippensteel, American tennis player
• Kiryas Joel, New York
• Kohtla-Järve, Estonia
• Keila-Joa, Estonia
• KJHK
• Kitchen Jerks, a way of life
• Kodomo no Jikan, a manga
• Kristen Jendras, a nickname for the usual Unit Leader of Kicoomba... and sometimes Innisfree.
• KJ-52, Christian rapper.

de:KJ eo:Kj fr:KJ it:KJ ja:KJ ko:KJ nn:KJ ksh:KJ (Watt ?ßß datt?) fi:KJ