J9

J9, J09, J 9 or J-9 may refer to:

Military

 * Chengdu J-9, a designation assigned to a 1975 Chinese interceptor aircraft that never progressed beyond initial studies
 * HMS Cromarty (J09), a 1940 British Royal Navy Bangor-class minesweeper
 * Junkers J 9, a factory designation for the 1917 German Junkers D.I fighter aircraft
 * Seversky J9, a Swedish WW2 fighter plane'

Transport

 * County Route J9 (California), a main route between the cities of Oakdale, Waterford, and Turlock
 * GS&WR Class J9, a Great Southern and Western Railway steam locomotive
 * Guinee Airlines, a defunct airline of Guinea
 * Jazeera Airways, a Kuwaiti airline
 * Malaysia Federal Route J9, a major road in Johor, Malaysia
 * Peugeot J9, a fullsize van manufactured from 1981 to 2010

Other uses

 * J9 (album), a 2004 album by Jolin Tsai
 * J9 Series, a trilogy of Japanese anime robot series
 * Elongated pentagonal pyramid (J9), a Johnson solid
 * IBM J9, an implementation of Java
 * S/2000 J 9, now called Taygete, a retrograde irregular satellite of Jupiter
 * S/2001 J 9, now called Orthosie, a natural satellite of Jupiter
 * S/2003 J 9, a retrograde irregular satellite of Jupiter