X-1 may refer to:

Transportation

Aircraft

  • Bell X-1, the first aircraft to exceed the speed of sound in controlled level flight

Automobiles

  • Lada X-1, a 1981 Soviet concept MPV
  • McLaren X-1, a 2012 British one-off sports car based on the 12C

Cycles

  • Sinclair X-1, an electrically assisted faired recumbent bicycle
  • Yamaha X-1, a commuter-style motorbike

Watercraft

  • X-1 Submarine, the United States Navy's only midget submarine

Technology

  • Xbox One, a video game console
  • a one-lane PCI Express slot

Arts, entertainment, and media

  • X Minus One, a 1950s American radio show
  • X-Men (film), the first film in the X-Men franchise
  • X-One, monthly magazine produced by Imagine Publishing

Other

  • x<sup> −1</sup>, the multiplicative inverse of x (another way to denote 1⁄x, one divided by x)
  • Cygnus X-1 and Scorpius X-1, two astronomical x-ray sources
  • M82 X-1, a candidate intermediate-mass black hole detected in January 2006

See also

  • X1 (disambiguation)
  • 1X (disambiguation)