Greg Kenton
The protagonist of the story, Greg, is a fifth-grade student and a budding entrepreneur. He is passionate about making and selling his own comic books.
Maura Shaw
Maura is Greg's classmate and his biggest competitor. She is also a talented artist and starts her own greeting card business, competing directly with Greg.
Mr. Zender
Greg's homeroom teacher, Mr. Zender is supportive of Greg's entrepreneurial endeavors and encourages his creativity. He provides guidance and advice to Greg throughout the story.
Dave Packer
Dave is Greg's best friend and a fellow comic book enthusiast. He helps Greg with his business ventures and supports him during challenging times.
Principal Winston
The principal of Greg's school, Principal Winston is portrayed as strict and focused on rules and regulations. He becomes a significant obstacle to Greg's entrepreneurial activities.
Barry Tuckerman
Barry is another classmate of Greg's, who constantly bullies him. He tries to sabotage Greg's business and create obstacles for him.
Mrs. Kenton
Greg's mother is supportive of his creative pursuits but also encourages him to balance his business aspirations with his schoolwork and other responsibilities.