U1, U.I or U-1 may refer to:

MathematicsEdit

MilitaryEdit

EntertainmentEdit

PeopleEdit

  • U1, alias for Yuvan Shankar Raja (born 1979), a Tamil musician and film composer
  • U-1, the main character in the video game Gitaroo Man for the PlayStation 2/PlayStation Portable

RailwaysEdit

  • LNER Class U1, a 1924 British solitary 2-8-0+0-8-2 Beyer-Garratt locomotive
  • SR U1 class, a class of 2-6-0 locomotives developed from the U Class

U-Bahn linesEdit

TechnologyEdit

OtherEdit

See alsoEdit