Años 60. Una joven de 17 años criada por una madre soltera no religiosa en una zona rural de Tennessee decide convertirse en monja, pero durante su noviciado comienza a cuestionar su fe católica.
 | Dianna Agron | Sister Mary Grace |
| Julianne Nicholson | Nora Harris |
| Margaret Qualley | Sister Cathleen |
| Liana Liberato | Sister Emily |
| Morgan Saylor | Sister Evelyn |
| Eline Powell | Sister Candace |
 | Melissa Leo | Reverend Mother |
| Chris Zylka | Chuck Harris |
| Maddie Hasson | Sister Sissy |
| Denis O'Hare | Archbishop McCarthy |
| Ashley Bell | Sister Margaret |
| Rebecca Dayan | Sister Emanuel |
| Chelsea Lopez | Sister Charlotte |
| Marco St. John | Father Luca |
| Lacy Hartselle | Sister Theresa |
