Hamilton "Buddy" Barrett is an eight year old BSC charge in third grade who is the older brother of Suzi Barrett and Marnie Barrett, the son of Natalie Barrett, and the stepson of Franklin DeWitt. His stepsiblings include Lindsey, Taylor, Madeleine, and Ryan Dewitt. He is a member of the Barrett/DeWitt Family. He makes his first appearance in Dawn and the Impossible Three.
Buddy is described as an active and lively kid that's skinny with big knobby knees and a mischief maker.
In Mallory and the Mystery Diary he wasn't reading at the proper reading level. Mr. Moser is his third grade reading teacher. Buddy says he hates flashcards amost as much as he hates Mr. Moser. Mallory Pike tutors him successfully by introducing him to comics books to make him a better reader. He moves from the lowest reading group to the middle reading book in his class.
He figures out that the moondust they ordered through the mail is a lie. He and the other do traveling salesmen show to earn money in Stacey's Choice.
In Maid Mary Anne he gets into fights over his participation in Mary Anne's sewing class. He goes overboard in proving his masculinity.
His favorite sitter is Dawn.
- Dragon Warriors a show that comes on at eight.
- Encyclopedia Brown
- Reading (but likes it later)
- Buddy is a picky eater.
- Is "The World's Greatest Animal Trainer" in a talent show that is hosted in the Pikes' backyard.
- He sings in All the Children of the World.
- In Save the Planet class he and Billy work an animal booth at the Green fair.
- Buddy and Suzi perform a Mother's Helper play.
- He is the ring bearer at his mother's wedding.
- Buddy shares his room with Taylor DeWitt.
- In Baby-sitters' Summer Vacation Logan says that he knows sign language to communicate with Matt. He substitutes for Matt at second base for the Krashers.
- Buddy has a small crush on Shannon Kilbourne in Kristy's Mystery Admirer.