Laura Helene Prepon (born March 7, 1980) is an American actress. She rose to fame with her role as Donna Pinciotti in the Fox sitcom That '70s Show (1998–2006). She is also known for her portrayal of Alex Vause in the Netflix comedy-drama series Orange Is the New Black (2013–2019). Prepon made her film debut in 2001 with the independent drama Southlander. Her other films include the romantic drama Come Early Morning (2006), the comedy Lay the Favorite (2012), the thriller The Girl on the Train (2016), and the drama The Hero (2017).
Prepon was born on March 7, 1980, in Watchung, New Jersey. She is the youngest of five children of Marjorie (née Coll), a high school teacher and gourmet home chef, and Michael Prepon, an orthopedic surgeon. Prepon's father died during heart surgery in 1993 at age 49; she was 13 years old at the time. She attended Watchung Hills Regional High School and later studied at the Total Theatre Lab in New York City. Her father was Jewish, of Russian-Jewish descent, and her mother has Irish Catholic ancestry. Her maternal great-great-great-grandfather was Union Army General Joseph Bradford Carr.