* Mrs. Jewls: The no-nonsense principal of Wayside School. She is strict and often resorts to extreme measures to maintain order, such as locking the students in the classroom and suspending them. She doesn't believe anything and is always ready with threats of the "horrid hole."
* Louis: Todd's best friend. He is creative but a bit timid and often follows Todd's lead.
* Maurecia: A third-grader who is very intelligent and quick-witted. She is often the voice of reason among her classmates.
* Dana: A third-grader who is very athletic and loves to play sports. She is also very competitive.
* Leslie: A third-grader who is very kind and caring. She is often the one to defuse tensions among her classmates.
* Sammy: A third-grader who is very shy and timid. He is often picked on by the other students, but Todd and his friends always stand up for him.
* Myron: A third-grader who is very curious and loves to explore. He is often the first to discover the weird and unusual things that happen at Wayside School.
* Joy: A third-grader that only speaks in whispers.