Pennsylvania, 1993. After getting caught with another girl, teenager Cameron Post is sent to a conversion therapy center run by the strict Dr. Lydia Marsh and her brother, Reverend Rick, whose treatment consists in repenting for feeling “same sex attraction.” Cameron befriends fellow sinners Jane and Adam, thus creating a new family to deal with the surrounding intolerance.

A crime she committed in her youthful past sends Piper Chapman to a women's prison, where she trades her comfortable New York life for one of unexpected camaraderie and conflict in an eccentric group of fellow inmates.