Paul is the supervising officer of Cold Mountain State Penitentiary's E Block, commonly known as the Green Mile. A calm and authoritative leader, he commands the respect of his fellow guards and treats the condemned inmates with baseline human dignity. In his present day at the Georgia Pines retirement home, he reflects on the heavy moral choices he faced during his career, particularly concerning a unique inmate named John Coffey.

John Coffey is a massive black man sentenced to death for the horrific murder of the Detterick twin girls. Despite his intimidating size and the gruesome nature of his convicted crimes, he exhibits a remarkably gentle, childlike demeanor and a deep fear of the dark. He possesses a mysterious healing touch that challenges the guards' understanding of reality and justice.

William Wharton, who insists on being called Will Bonney or The Kid, is a nineteen-year-old inmate arriving on the Green Mile after a wild crime spree. He is entirely remorseless, violently unpredictable, and highly intelligent when it comes to manipulating his surroundings. He delights in causing chaos and terrorizing both the guards and his fellow inmates.

Percy is a young, sadistic guard on the Green Mile who uses his family's political connections to avoid accountability. He lacks the temperament for correctional work, preferring to bully and abuse inmates who cannot fight back. His presence creates a toxic and dangerous environment for both the prisoners and his fellow officers.

Eduard Delacroix is a slight Cajun man condemned to the electric chair for severe crimes. Despite his dark past, his behavior on the Green Mile is timid and compliant. He finds a sliver of joy and redemption in his friendship with a remarkably intelligent prison mouse, which becomes his sole focus as he awaits his execution.

Brutus Howell is Paul Edgecombe's trusted second-in-command on the Green Mile. Despite his intimidating nickname and large physical stature, he is fundamentally decent and highly empathetic toward the inmates. He uses his imposing presence to maintain order and effectively check Percy's worst impulses, serving as Paul's most reliable ally.

Initially called Steamboat Willy by the guards, Mr. Jingles is a remarkably intelligent mouse that takes up residence on the Green Mile. He displays an uncanny ability to read human emotions, showing favor to kind individuals while actively avoiding Percy. The mouse becomes a focal point of empathy and wonder within the bleak environment of death row.

Janice is Paul's loving and highly perceptive wife during his years working at Cold Mountain. She provides him with emotional grounding and an essential sounding board for the heavy psychological toll of overseeing executions. She is fiercely loyal and possesses a strong sense of moral justice.

Hal Moores is the pragmatic but compassionate warden of Cold Mountain State Penitentiary. He respects Paul's leadership on E Block and relies on him to keep operations smooth. However, Hal's professional competence is severely tested by personal tragedy as he watches his beloved wife battle a debilitating illness.

Melinda is the kind and gentle wife of Warden Hal Moores. As a severe brain tumor progresses, it tragically alters her personality, causing her to swear and behave erratically. Her dire medical condition casts a shadow over the prison administration.

Brad is an abusive, manipulative orderly tasked with caring for the elderly residents at Georgia Pines. He takes sadistic pleasure in intimidating those who are too frail to defend themselves. For Paul Edgecombe, Brad serves as a chilling, modern-day echo of Percy Wetmore.

Elaine is Paul's companion at the Georgia Pines retirement home. Sharp-witted and fiercely protective, she reminds Paul a great deal of his late wife, Janice. She leverages her impressive family connections to shield Paul from abusive staff members and serves as the primary audience for his written memoir.

Dean is one of the regular guards assigned to E Block. He is a capable and reliable officer who generally follows Paul's lead. His sense of security on the job is shattered when he is nearly choked to death by William Wharton during the inmate's deceptive arrival.

Harry is a steady, dependable guard on the Green Mile who helps maintain the delicate balance of death row. He is practical and occasionally provides crucial logistical support for Paul's more unorthodox plans concerning the inmates.

Klaus is the grieving father of Cora and Kathe, the murdered twin girls. Devastated by the brutal crime, he participates in the search party that ultimately finds John Coffey with the bodies. His overwhelming sorrow and rage define his presence in the story as he seeks justice for his family.

Marjorie is the mother of the murdered twins. After allowing her daughters to sleep on the porch on a warm night, she faces the unimaginable horror of their abduction. The trauma ages her significantly, and she harbors a deep hatred toward the man convicted of the crime.

Arlen Bitterbuck, respectfully referred to as The Chief, is a Native American inmate sentenced to death for killing a man during a drunken altercation. He approaches his impending execution with a quiet dignity, speaking with Paul about his beliefs regarding the afterlife and his past life in Montana.

Toot-Toot is an inmate trusty who handles odd jobs around Cold Mountain, such as delivering meals and selling small goods to the condemned men. He also serves as the darkly comedic stand-in during the guards' execution rehearsals, famously making crass jokes while strapped into the electric chair.

Burt is a reporter for the Tefton Intelligencer who covered John Coffey's arrest and trial. He harbors deeply ingrained prejudices, using a disturbing analogy involving a rabid family dog to explain to Paul why he firmly believes Coffey is a remorseless killer, regardless of his docile behavior.