Narrator Dave Sexton is the protagonist of "Split Cherry Tree." His father, Luster, makes a pistol-packing surprise visit to school; and Professor Herbert is the firm-handed teacher who quells the father's anger. Other minor characters include:

DAVE'S MOTHER, who seems level-headed but subservient to her domineering husband.

"Now, Luster," says Mom, "you jist stay away from there. Don't cause a lot o' trouble. You can be jailed fer a trick like that. You'll get th' Law atter you. You'll jist go down there and show off and plague your own boy Dave to death in front o' all th' scholars!

EIF CRABTREE, whose cherry tree is damaged by a group of boys on the field trip and demands payment for his loss.

FRED WUTTS, a classmate of Dave's.

GLENN ARMSTRONG, a classmate of Dave's.

The narrator: a young man fearful of and embarrassed of his father; he thinks his father will shoot his teacher.

He tells Professor Herbert:

"He might be called a little old-fashioned. He makes us mind him until we're twenty-one years old. He believes: 'If you spare the rod you spoil the child.' I'll never be able to make him understand about the cherry tree. I'm the first of my people to go to high school."

Professor Herbert: the principal of the school who punishes the narrator for breaking down the cherry tree.  Later, he will show the boy's father the microscopic world, which will induce an apology from him.

He tells the narrator:

"You must take the punishment.  You must stay two hours after school today and two hours after school tomorrow. I am allowing you twenty-five cents an hour. That is good money for a high-school student. You can sweep the schoolhouse floor, wash the blackboards, and clean windows. I'll pay the dollar for you."

The boy's father: uneducated, working class, old-fashioned, conservative, uses his gun to solve problems, suspicious of liberal education.  He will help his son pay off the damage by the end.

He says:

"I'm a poor man. A bullet will go in a professor same as it will any man. It will go in a rich man same as it will a poor man. Now you get into this work before I take one o' these withes and cut the shirt off'n your back!"