Leila Vaziri (born 6 June 1985) is an American swimmer and World Champion in the 50m backstroke.
Leila Vaziri was the daughter of Mansour and Lise Vaziri and grew up in Coral Springs on Florida, where she attended high school. During her high school years she was three-time high school champion of the State of Florida. Since 2003, she attended the Indiana State University and serves on the swim team at the university.
In August 2006, she won the U.S. Championships, ConocoPhillips National Championships 100m backstroke and in November 2006 she was in this discipline second at the U.S. Open.
On 28 March 2007, the World Swimming Championships in Melbourne she improved the world record in the semifinals in the 50m backstroke in 28.16 seconds after they had already set up a new Jahresbestleistung in the heats. In the final on 29 March 2007, it terminated this world record, and thus became world champion.