J12

J12 may refer to:

Aircraft

 * Nanchang J-12, a prototype Chinese fighter

Automobiles

 * Hispano-Suiza J12, a French luxury car
 * Subaru J12, a Japanese hatchback

Ships

 * HSWMS Sundsvall, a Visby-class destroyer of the Swedish Navy

Other uses

 * Chanel J12, a Swiss-made watch
 * County Route J12 (California)
 * Triangular bipyramid, a Johnson solid (J12)
 * Marlboro Pike Line, a bus route in the Washington Metro Area
 * Viral pneumonia