Mark Twain: The pen name of Samuel Clemens, author of The Adventures of Huckleberry Finn on which Big River is based.
Huckleberry Finn: A poor teenaged boy, with no mother. His father is a violent drunk who is rarely around. Huck had been homeless, living in a large barrel. Through a series of adventures told in the story of Tom Sawyer, Huck had gained a small fortune of $6000. At the beginning of the play, he had been taken in and cared for by two sisters.
Widow Douglas and Miss Watson: Two sisters who are taking care of Huck and his education. They both care very much about religion. Miss Watson is a slave owner.
Jim: A slave belonging to Miss Watson, Jim has run away to find his family. He is very superstitious but knows Huck and cares for him as they journey down the river.
Tom Sawyer: Huck’s friend, Tom is a teenaged boy who loves adventure novels.
The Gang of Boys: Ben Rogers, Jo Harper, and Simon are teenaged boys living in St. Petersburg, Illinois.
Pap Finn: Huck’s father, Finn is a vagabond drunkard who loves whiskey and hates the government. Tries to get at Huck’s money.
Judge Thatcher: The trustee managing Huck’s money for him.
Strange Woman: A woman new to the town of St. Petersburg, she knows enough to know what’s going on with the search for Huck’s body and his murderer, but not enough to know that the person she is talking to is Huck.
The King and the Duke: Charlatans and conmen who tell Huck and Jim they are royalty, their goal is to make money any fast way they can, favoring methods that include lying.
Mary Jane, Susan, and Joanna Wilkes: Daughters in a well-off family, their father recently died. These trusting women who are almost taken in by the machinations of the King and the Duke.
Counselor Robinson: A lawyer, he cautions the Wilkes daughters against trusting the King and Duke.
Alice and Her Daughter: Slaves belonging to the Wilkes family.
Sheriff Bell: The local sheriff.
Harvey Wilkes: The real uncle of the Wilkes daughters.
Sally Phelps: Tom Sawyer’s aunt.
Silas Phelps: Tom Sawyer’s uncle.
Doctor: He helps save Tom from a gunshot wound and defends Jim.