John Coffey, one of the main characters in Stephen King's serial novel "The Green Mile". He is a black man who stands almost seven-foot tall. He is convicted of raping and killing two small white girls. He is notable because of his size and also for his strange behaviour; he is very quiet and prefers to keep to himself, he weeps almost constantly, and is afraid of the dark. Coffey is described as "know[ing] his own name and not much else", and lacks the ability to so much as tie a knot, yet he is convicted of luring the girls away from their home, disposing of the watchdog, carefully planning and using abilities he would otherwise not be expected to have. He's the calmest and mildest prisoner the warders have ever seen, despite his hulking form. Besides John Coffey, there are two other prisoners on the cell block during the main period the book focuses on. One of them, Eduard Delacroix, a convicted arsonist, rapist, and murderer, is small and cowardly (the actions which led to his conviction being described as "the only crime he had in him"). The other, William Wharton, is tough and boasting, claiming to be a modern Billy the Kid. When Paul looks even before the 1930's, he recollects about warding the Chief, a Native American named Arlen Bitterbuck, and the Prez, a former CEO who killed a relative, hoping to collect life insurance money.

The story also features Mr. Jingles, a small and unnaturally intelligent mouse who befriends Delacroix. He appeared much earlier than Delacroix, and Paul speculates he was looking for the Cajun. The mouse learns various tricks and appears to follow commands; Delacroix insists that the mouse whispers things in his ear. After the two meet, Delacroix practically falls in love with the mouse, and Mr. Jingles ceases his cell-searching.

Over time, the warders realize that there is something else special about John Coffey, as he is revealed to possess mystical healing abilities. These powers heal Paul's urinary infection, the warden's wife's brain tumor, and Mr. Jingles broken form (courtesy of Percy Wetmore, a prissy jailor who hated Delacroix). They are faced with the terrible truth that they must execute what they call a "gift from God". They finally execute Coffey, but not before he passes on an unnatural lifespan to both Mr. Jingles and Paul. In the end, Mr. Jingles dies of old age at the age of 64 in Paul's nursing home, Paul reveals to the reader how his wife died, and we learn that Paul is 104 years old, and how he wonders how much longer he's got to stay. The book ends with this quote: "We each owe a death, there are no exceptions, I know that, but sometimes, oh God, the Green mile is so long."