U.S. Open

U.S. Open usually means:
US Open (tennis)
U.S. Open (golf)

Other uses include:
 U.S. Open Badminton Championships
 U.S. Open Beer championship
 U.S. Open (bowling)
 U.S. Open Chess Championship
 U.S. Open (crosswords)
 U.S. Open (cycling)
 US Open (darts)
 U.S. Open (go), boardgame tournament
 U.S. Women's Open, golf tournament
 US Open (martial arts), also called ISKA World Martial Arts Championship
 US Open Polo Championship
 U.S. Open pool championships
 U.S. Open Rubik's Cube Championship
 Lamar Hunt U.S. Open Cup, soccer (association football) tournament
 U.S. Open (squash)
 U.S. Open (swimming)
 U.S. Open of Surfing
 U.S. Open (taekwondo)
 U.S. Open (USACO), United States of America Computing Olympiad, programming competition
 US Open USTA Wheelchair Tennis Championships
 U.S. Open (wrestling)