The Junkers J 5 was a designation assigned to several fighter aircraft designs.
In early 1917, Junkers developed at least two cantilever wing monoplane fighter aircraft designs based on the J4.[1]
The first design, known as the J 5I, was to have a Siemens Sh2 or Oberursel UR.II engine behind the cockpit.
The second design was to have the engine in front of the pilot.
A third design was also developed under the designation J 5III (later J 6) with a Mercedes D.IIIa and a parasol wing.