Born March 7, 1980 in Watchung, NJ to father, Michael (an orthopedic surgeon), and her mother, Marjorie (a teacher), Prepon was fifth-born in a family that included a brother, Brad and three sisters, Danielle, Jocelyn and Stephanie. Unfortunately for the tight-knit siblings, their father died in 1993 from complications during heart surgery. Prepon attended Watchung Hills Regional High School, until she caught the acting bug at age 15, deciding to quit regular school and transferred to Total Theatre Lab, a specialized theater college based in New York City. As she continued to hone her acting skills, Prepon appeared in such plays as “A Woman of Property” and Ascension Day,” as well as began to study dance – ballet, jazz and modern. Due to her striking, unique look, the aspiring actress soon began landing modeling jobs both stateside and abroad, jetting around the world to fabulous locations such as Paris and Milan. Despite the glamour of it all, Prepon grew disillusioned by the cutthroat nature of the modeling world. Ironically (perhaps laughably), Prepon felt that showbiz would be less competitive, so she changed careers midstream.

Prepon’s life changed forever when she sent an audition tape to the creators of “That 70's Show” – a show about teenage buddies growing up in Wisconsin during the carefree 1970s. The creators loved her, sending her a plane ticket to Los Angeles to audition one-on-one with the top contenders. Of course, Prepon won the role and was perfectly suited to playing Donna Pinciotti, the dry humored girl-next-door of the group. The show was a hit from the start, lasting eight years.

With her profile raised by the hit show, Prepon became a vital part of the new millennium’s young Hollywood scene. With little on her pre-“’70s” resume, Prepon started landing roles in smaller movies, making her debut in “Southland: (2001), followed by “Slackers” (2002) and “Pornographer: A Love Story” (2004). Prepon contributed a guest voice on Fox’s “King of the Hill” (1997- ) in 2004 and breathed life to an embattled marine in the hit Xbox game, “Halo 2.” If doing video game voice-overs was not enough to solidify her geek bait status, the ravishing redhead was ranked #50 in Maxim magazine's "Hot 100 of 2002" supplement, as well as #84 in Stuff magazine's "102 Sexiest Women in the World” that same year.