Tom Joad
Tom returns from prison already marked as someone the system has chewed up. He tries to stay neutral and keep his head down, but watching Casy get killed forces him to choose a side. His arc is the novel's moral spine — from self-preservation to collective action.
Ma Joad
Ma is the emotional and practical center of the family. When Pa loses his confidence and authority, Ma steps in and makes the decisions. She holds the family together through sheer stubbornness and love, and she is the one who lets Tom go when she understands what he has to do.
Jim Casy
Casy is a former preacher who has stopped believing in conventional religion but started believing in people. He volunteers to take the blame when Tom gets in trouble, goes to jail, and comes out as a labor organizer. His death turns Tom into an activist.
Rose of Sharon (Rosasharn)
Rose of Sharon starts the novel as a self-absorbed young woman excited about her pregnancy and her future with Connie. The migration strips everything away — her husband, her baby, her plans. Her final act of nursing a stranger is Steinbeck's image of grace born from total loss.
Pa Joad
Pa is the nominal head of the family but loses authority steadily as the migration defeats him. He can't provide, can't protect, and can't lead. His decline tracks the destruction of the traditional male provider role under economic collapse.
Grandpa and Grandma Joad
Both die early in the journey. Grandpa is torn from the land he loves and dies almost immediately. Grandma holds on until the family crosses into California, then lets go. Their deaths signal that the oldest generation cannot survive displacement.
Al Joad
Tom's younger brother is obsessed with cars and girls, but he keeps the Hudson running across the country. He eventually falls in love and chooses to stay with his fiancée rather than follow the family — another piece of the family breaking off.
Uncle John
Uncle John carries a crushing sense of guilt from his past and drinks to manage it. He is unreliable but not cruel. Steinbeck uses him to show how private shame becomes another burden the poor carry on top of everything else.