George
George Milton. A migrant worker who travels from farm to farm with his mentally impaired friend Lennie during the Depression. The two dream of earning enough money to buy a small farm where Lennie can tend rabbits. By virtue of his mental superiority, George assumes a dominant role with Lennie, acting as a parent. Because Lennie tends to involve George in difficult predicaments, George must be responsible, level-headed and ready to deal with any tragedy that may arise. Despite the many problems that Lennie causes George, he stays with his simple-minded friend as a buffet against loneliness and he retains a palpable hope that the two will eventually leave the aimless life of a migrant worker to live a more fulfilling existence.
Lennie
Lennie Small. A gigantic, mentally disabled man, Lennie is simplistic and docile. He obsesses over simple sensory pleasures, particularly finding great joy in touching soft things, whether a cotton dress or a soft puppy. Although Lennie is inherently innocent, he is still capable of great violence, for he lacks the capacity to control himself physically and has a great protective instinct, especially when it comes to his friend, George. Lennie dreams with George of having a small piece of land; he is obsessed with one aspect of this dream: having a small rabbit hutch where he can tend rabbits. Lennie is incapable of making decisions by himself and relies on George entirely.
Candy
An old, crippled man who has lost his hand, Candy is the swamper at the ranch. He remains attached to his aging dog, who has become so weak and sickly that it depends entirely on Candy to survive. Still, when Carlson objects to the dog's smell, Candy allows Carlson to put the dog out of its misery. Candy is a passive man, unable to take any independent action. Indeed, his one major act in the book - when he offers Lennie and George money in order to buy a piece of land with them - is a means by which he can become dependent on them.
Curley
The son of the ranch owner, Curley is a man of short stature who is nevertheless a formidable boxer. Curley is aggressive, boastful and cocky, with a volatile temper and a tendency to provoke conflict with the weak, as he does with Lennie. Part of Curley's bravado stems from anxiety over his new wife, who everyone widely suspects of being "a tramp." He spends a great deal of time monitoring her, believing her to be off with other men when she is not under his supervision.
Curley's wife
Generally considered to be a tramp by the men at the ranch, Curley's wife is the only major character in Of Mice and Men whom Steinbeck does not give a name. She dislikes her husband and feels desperately lonely at the ranch, for she is the only woman and feels isolated from the other men, who openly scorn her. She still holds some small hope of a better life, claiming that she had the chance to become a movie star in Hollywood, but otherwise is a bitter and scornful woman who uses sex to intimidate the workers. Lennie accidentally murders her.
Crooks
The stable buck at the ranch, Crooks is also the only black man in the novel. A proud and bitter man, Crooks has a cynical intelligence and a contemptuous demeanor that he uses to prevent others from inevitably excluding him because of his race. His defensive manner fades, however, once Lennie behaves kindly toward him, and he even considers helping Lennie and Candy with their plan to buy land until the threats by Curley's wife force him back into his normal combative posture.
Carlson
A large, big-stomached man who works at the ranch, Carlson complains about Candy's dog and eventually offers to put the old dog out of its misery. George steals Carlson's gun to shoot Lennie after Curley's wife is murdered.
Slim
The jerkline skinner at the ranch, Slim is a seemingly ageless man who carries himself with great gravity. He gives Lennie one of his new litter of puppies to care for. Curley initially suspects that his wife is having an affair with Slim.
Whit
He is one of the workers at the ranch, a young man who shows Carlson the magazine with the letter from William Tenner.
The Boss
The boss of the ranch is Curley's father. He acts suspiciously of George and Lennie when they arrive, thinking that there's something odd about the two mismatched companions.
Aunt Clara
The woman who raised Lennie. Though deceased, she appears to Lennie in a hallucination when he hides in the brush in Chapter Six. In this hallucination, she appears as a short but hefty woman who berates Lennie for his stupidity.
William Tenner
A former worker at the ranch who drove a cultivator, Whit shows Carlson a magazine that has a letter to the editor that Bill Tenner has written.
Andy Cushman
An acquaintance from grammar school, George tells Lennie that he is now in jail in San Quentin "on account of a tart."
Al Wilts
The deputy sheriff of Soledad. Curley sends Whit to find him when his wife is murdered.