Red is a seasoned inmate at Shawshank prison serving consecutive life sentences. Having arrived at the age of twenty after tampering with his wife's car brakes, he accepts his guilt and operates a highly effective smuggling ring inside the prison. He holds a unique position among the prisoners because he knows how to procure outside contraband, such as cigarettes and rock hammers. He generally avoids thinking about the future, preferring a cynical but pragmatic approach to surviving his incarceration.

Andy is a former successful banker who receives a life sentence for the murders of his wife and her golf-pro affair partner. He maintains a calm, composed demeanor that sets him apart from the rest of the prison population, wearing his dignity like an invisible shield. Educated and articulate, he faces immediate brutality from predatory inmates but uses his financial acumen to carve out a safer position for himself. He collects and shapes rocks as a hobby while actively working to expand the prison library.

Samuel Norton is the cruel and hypocritical administrator of Shawshank prison. He presents himself publicly as a devout Christian who requires prisoners to read the Bible, while secretly orchestrating extensive illegal enterprises and taking cuts from prison labor projects. He uses the threat of solitary confinement to maintain absolute obedience and forces Andy to launder his dirty money.

Tommy is a young, uneducated career criminal serving time for burglary. He has a wife and a young son on the outside, which motivates him to try and improve his life through education. He enrolls in the high school equivalency program at the prison library and takes an immediate liking to Andy, eventually revealing crucial information from his past.

Byron Hadley is a notoriously brutal lead guard at Shawshank prison. He is a bitter man who harbors simmering rage at life's unfairness and maintains order through severe physical intimidation. He benefits directly from Andy's financial advice, establishing a strange transactional protection for the former banker.

Bogs Diamond is a large inmate and the leader of a sadistic prison gang known as "the sisters." He preys on new, seemingly weak prisoners, utilizing physical intimidation and sexual violence to exert dominance within the prison hierarchy.

Elwood Blatch is a boastful criminal who previously served time alongside Tommy Williams. He openly brags about his outside crimes, including a specific double murder involving a local golf pro that significantly impacts Andy's life.

Glenn Quentin is a local golf club professional. His involvement with Andy's wife leads to a highly publicized media spectacle and serves as the catalyst for Andy's eventual imprisonment at Shawshank.

Jim is an external friend and financial associate of Andy prior to the latter's imprisonment. He assists Andy with moving money and managing investments in the outside world, setting up secure accounts under a false identity.

Rooster is an inmate at Shawshank prison and a member of the predatory gang led by Bogs Diamond. He actively participates in the group's brutal assaults on newer inmates until he sustains a broken nose during a scuffle with Andy.

Mert Entwhistle is a guard at Shawshank prison who works alongside Byron Hadley. He observes the tense interactions between the inmates and the more volatile members of the prison staff during labor projects.

Rich Gonyar is a guard at Shawshank prison tasked with maintaining daily routines. He interacts directly with the warden during high-stress institutional procedures but demonstrates enough self-preservation to refuse particularly dangerous orders.