The US Open, formally the United States Open tennis championships, is a tennis tournament which is the modern incarnation of one of the oldest tennis championships in the world, with the U.S. National Championship, which for mens' singles was first contested in 1881. Since 1987, the US Open has been chronologically the fourth and final Grand Slam tennis tournament each year.

It is held annually in August and September over a two-week period. Since 1978, the tournament has been played on acrylic hard courts at the USTA Billie Jean King National Tennis Center at Flushing Meadows in Queens, New York City.