Sarah Shahi was born Aahoo Jahansouz in Euless, Texas, to an Iranian father and Mexican mother. She is a former National Football League cheerleader and a great-great-granddaughter of the 19th-century Persian Shah Fath Ali Shah Qajar by Begom Khanom (daughter of Hossein Qoli Khan Afshar, niece of Begom Khanom, daughter of Emam Qoli Khan Afshar), through their son Jahansouz Shah. She attended Trinity High School and Dallas' Southern Methodist University, majoring in English and opera. 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, which she did. She had recurring roles in several TV series, such as "Alias" (2001), in which she played Jenny; "Dawson's Creek" (1998), where she was Sadia Shaw; and "The L Word" (2004), playing Carmen de la Pica Morales. Shahi was also the first ghost in "Supernatural" (2005), the CW paranormal drama series.
She is best known for her role as the Mexican-American DJ Carmen de la Pica Morales in the Showtime series "The L Word", which she joined in its second season. Sarah did not renew her contract with the the show for a fourth season, and consequently her character was written out.
She also appeared in HBO's "The Sopranos" (1999), in the Season 6b episode "Kennedy and Heidi", as Sonya Aragon, a stripper and college student who spends a weekend with Tony after a death in his family. 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. She also starred with Damian Lewis in the NBC show "Life" (2007).
Sarah speaks English, Persian and some Spanish, and has a brown belt in karate.