J40

J40 may refer to:
 * County Route J40 (California)
 * Elongated pentagonal orthocupolarotunda, a Johnson solid (J40)
 * HMS Fermoy (J40), a Hunt-class minesweeper of the Royal Navy
 * Toyota Land Cruiser (J40), a Japanese off-road vehicle
 * Westinghouse J40, an American turbojet engine