James "Stink" Moody is Judy Moody's little brother. He reads encyclopedias a lot and joins the Toad Pee Club. He has Toady, his pet mascot for the club.
- Judy Moody - Stink's moody big sister.
- Kate - The mother of Stink and Judy and the wife of Richard.
- Richard - The father of Stink and Judy and the husband of Kate.
- Grandma Lou - Stink and Judy's grandmother.
- Opal Moody - Stink and Judy's aunt and Richard's sister.
- Rocky Zang - Judy's best friend.
- Frank Pearl - Judy's "pest" friend
- Tori - Judy's pen pal from England. She has everything that Judy never has: many sleepovers, a phone, a washcloth, her own bathroom, and pounds of allowance. She is a big fan of Bonjour Bunny.
- Laura Chumsky - An African-American little girl in a wheelchair who has had a heart replacement. She is getting a hamster when she goes home. She is given a doll that looks just like her, like the newspaper said.
- Hannah - A girl who comes to see Judy's pit in Judy Moody Gets Famous
- Ricky - Hannah's little brother. He eats Judy's pit because he thinks it's an M&M.
- Zeke - Stink's teenage friend who is the president of the BBA (Bigfoot Believers Association). He appears in Judy Moody and the NOT Bummer Summer.
- Herb - A member of the BBA.
- Webester- stink's best friend
- Rose - A member of the BBA.