Sarah Shahi was born Aahoo Jahansouz in Euless, Texas, to an Iranian father and Spanish mother. She is a former NFL cheerleader and a descendant of a 19th-century Persian Shah. She attended Trinity High School and Dallas Southern Methodist University, studied opera and majored in English. As a teenager, she won several beauty contests, and took first place in the Miss Fort Worth USA pageant in 1997. She joined the Dallas Cowboys cheerleaders and was part of the 1999-2000 squad. She also appeared on the cover of their 2000 calendar.
While working as an extra on the set of Dr. T and the Women (2000), she met director Robert Altman, who encouraged her to move to Hollywood to pursue a career as an actress. Although uncredited by most sources, Sarah also appeared in the Jackie Chan film, Rush Hour 3 (2007), as one of the girls being handcuffed along with Mia Tyler for traffic offense by Chris Tucker early in the film. Sarah speaks English, Farsi and some Spanish, and has a brown belt in karate.