Leila Vaziri (born June 6, 1985) is an Iranian-American swimmer. She was the world record holder in the 50 m women's backstroke, set on March 28, 2007 in the 2007 World Aquatics Championships in Melbourne, with a time of 28.16 seconds, until her time was bettered by Li Yang on October 19, 2007. She equalled the record in the finals race the day after.
She has an Iranian father and a mother of German ancestry.
Vaziri completed her collegiate swimming career at Indiana University. The 2007 NCAA bronze medalist in the 100-yard backstroke, Vaziri had already left an indelible mark in IU history prior to her World Championship heroics. Vaziri earned 15 All-America certificates during her Hoosier career, the most in school history.