Project X could refer to:

• a military project by Nazi Germany's Aviation Ministry to develop a rocket-powered interceptor aircraft. The project would result in the design and manufacture of the Messerschmitt Me 163.

• Project X, a 1987 movie starring Matthew Broderick.

• Project-X, a horizontally-scrolling shoot 'em up computer game for the Amiga, released by Team 17 in 1992.

• Project X, a late 1980s NYC straight edge hardcore punk band.

• a retail package sold by radio station WNNX-FM (99X) in Atlanta. Proceeds benefited a local charity. Project X contained the following items:
  • 1. Live X CD
    2. Interactive CD containing a video trivia game, screensavers, a customized web browser
    3. A calendar containing important dates
    4. A "big ticket" to be redeemed at future station events

• The Apple HotSauce software was called Project X in early stages of its development.