In 1947, a successful banker named Andy Dufresne is convicted of the double murder of his wife and her lover, despite his claims of innocence. Sentenced to two consecutive life terms, he is sent to Shawshank State Penitentiary. Inside the unforgiving walls of prison, Andy struggles to maintain hope and his sense of self. He is befriended by Ellis Boyd "Red" Redding, a long-term inmate and prison contraband smuggler who narrates Andy's story. Andy's background in finance gets the attention of the corrupt warden and the prison guards, leading him to perform financial chores for them, and later, for the warden's illicit business dealings.

Andy's intelligence and unbreakable spirit help him to win favor among inmates and prison staff alike. He begins to implement improvements within the prison, such as expanding the library and helping fellow inmates achieve their high school equivalency diplomas. However, despite his contributions to the inmate community and positive impact on the prison's operations, Andy's own dreams seem trampled by the oppressive system that holds him captive. The injustice and brutality of prison life are pervasive, experienced not only by Andy but by his friends, including Red. His endurance and innovative mind will become central to his struggle to retain his humanity within the oppressive walls of Shawshank, and his relationship with Red will prove pivotal to both their lives.