Bishil was born in Pasadena, California as the youngest of three children. Her mother is White American, and her father is a Saudi citizen of Indian descent. In 1991, when Bishil was three years old, the family moved to Saudi Arabia, later relocating to Bahrain, where she and her older brother attended Bahrain School.

The family returned to California in 2002, where she completed an independent study program for high school. She stated that the return was not easy: "I initially had some tough times trying to assimilate. It really makes you think about who you are and where you’re at.”

Bishil started acting lessons at age 14. Within a year, she was signed to a contract with a manager and agency. Bishil's first role was on the short-lived Nickelodeon show, Just for Kicks, followed by several appearances in children's shows before her break-through performance in Towelhead. Slate critic Dana Stevens said that "Her performance is the truest thing in a movie that, for all its good intentions, feels thoroughly phony and mildly embarrassing, like an extended PSA about inappropriate touching." Bob Strauss, who writes for several Los Angeles newspapers, states that Bishil, "...is one of the finest natural film actresses to emerge in years."[citation needed] Gary Goldstein of the Los Angeles Times in a September 12 review of the movie Towelhead, stated that, "...newcomer Summer Bishil turns in a gutsy, quietly riveting performance as Jasira."[citation needed]

In 2006, Bishil was chosen to play the lead in Alan Ball's film, Towelhead, an adaptation of the novel of the same name; it was with this role that she achieved wider fame.

In 2007, she filmed Wayne Kramer's project, Crossing Over, starring Harrison Ford, Ray Liotta and Ashley Judd.