Dear Dumb Diary is a series of children's novels by Jim Benton. Each book is written in the first person view of a middle school girl named Jamie Kelly. The series is published by Scholastic in English and Random House in Korean. Film rights to the series have been optioned by the Gotham Group.

The series follows the adventures and awkward incidents of Jamie Kelly at Mackerel Middle School with her friends Isabella and Angeline. Her family life and school life are heavily intertwined, with her Aunt Carol joining the school staff and marrying the assistant principal, thus making most of the school staff family friends.

Characters Main Jamie Kelly is an awkward, easily embarrassed middle school girl who owns the diary and narrates the stories. She is passionate about art and glitter and is generally thought of as weird or eccentric. She loves koalas and has coulrophobia. Jamie typically has a sarcastic nature and enjoys teasing and deriding those around her in her diary. While most of this is lighthearted, she particularly enjoys putting down her favorite targets including adults (which she even speculated are not human at one point) and authority figures such as her teachers and school staff, her friend Angeline, the lunchroom monitor Ms. Bruntford, the bully Pinsetti, her dog Stinker, other students, clowns, and on occasion her best friend Isabella, among many others. She is part of the Student Awareness Council and the Cuisine Club. Named after Jim Benton, whose full name is James Kelly Benton. She is portrayed by Emily Alyn Lind in the film adaptation. Isabella Vinchella is Jamie's mean and hotheaded best friend who is often manipulative, foul-tempered, prone to intimidation tactics, and even outright unpleasant, as a result of having grown up around two older brothers who enjoy bullying and belittling her. Regardless of these traits, Jamie insists on being her friend throughout everything, even admiring her for her violence as they became friends when Isabella beat up a boy for making fun of her name, and Jamie complimented her by comparing her to a "dangerous little mousetrap that you shouldn't put your fingers in". She is a master of faking injuries to frame her two mean older brothers for inflicting them. She is part of the Video Game Club. She is portrayed by Mary-Charles Jones in the film. Angeline is a beautiful and popular girl who, despite seeming to embody the mean popular girl stereotype in earlier books where Jamie sees her as more of an enemy, is actually very nice and loves donating to charities. She constantly strives to be seen as more than just beautiful and popular. She considers herself a very good friend of Jamie and her Aunt Carol and Uncle Assistant Principal Devon, and has helped them multiple times, despite Jamie believing she is plotting against her. In Am I The Princess Or The Frog? she is revealed to be Jamie's kindergarten friend known as "Annie" due to a speech impediment. Her last name is unknown, but her father's name is known to be Angelo. She is head of the Student Awareness Council. She is portrayed by Sterling Griffith in the film.

When writing about why she hates Angeline, Jamie often describes, in elaborate detail, Angeline's kindness, beauty (particularly her self-styled blonde hair), intelligence, and other positive qualities. Because of this, the seemingly superficial nature of their shared crush on Hudson, and other factors, some readers have interpreted Jamie as a closeted lesbian with a tsundere crush on Angeline. Jim Benton stated:

Major Stinker is Jamie's old and overweight male beagle, known for farting (hence the name) who despite Jamie believing him to be ugly and stinky, and often playing pranks on him, is very much well-loved. Along with Pinsetti, he is the source of most of the gross-out humor in the books. He is believed to have died in the book Dear Dumb Diary Deluxe: Dumbness Is A Dish Best Served Cold after swallowing Jamie's late grandmother's bracelet, but a miracle surgery funded by Jamie, Isabella and Angeline's partnership with the salad dressing company saves his life. He is portrayed by a Jack Russell Terrier in the film. Aunt Carol is Jamie's beautiful aunt who works as a secretary in Mackerel Middle School and is married to Uncle Assistant Principal Devon. While they were still dating, the identity of Devon as Aunt Carol's boyfriend was kept a secret, and Jamie kept force-feeding Stinker beans as an excuse for her to leave her room because of the smell of his farts, so she can eavesdrop on her mother and Aunt Carol's conversations. This does not succeed, and Stinker doesn't fart until the day of Carol and Devon's wedding at Jamie's house causing everyone to evacuate due to nearly a month's worth of gas from beans stewing in his belly. In the book The Problem With Here Is That It's Where I'm From, Isabella successfully tricks Aunt Carol into believing long white wedding dresses are no longer in style and that wooden clogs and brown poofy dresses are the latest fashion among young brides of Hollywood, but after Jamie and Isabella make a big show out of fake-falling down the stairs in the clogs, Carol ends up buying them new shoes. The poofy dresses were also stolen by Devon before the wedding. Aunt Carol is portrayed by Laura Bell Bundy in the film. Uncle Assistant Principal Dan Devon is Jamie's uncle and assistant principal of Mackerel Middle School, who is also Angeline's uncle on her mother's side, making Angeline Jamie's cousin-in-law. Jamie was disgusted by the marriage making her somehow related to Angeline and on occasion had tried to separate them. Due to being Jamie's uncle, he serves as Jamie's connection to the school when he wants her, Isabella and Angeline to plan out events. He is portrayed by James Waterston in the film. Jamie's mother is known for her horrible cooking which she attempts to force onto her daughter and husband, nevertheless she makes decent hors d'ouvres. In the book You Can Bet On That she is also known for making horrible clothes which she forces onto her daughter, husband and Isabella, described as looking like "monkey vomit". Aside from her gross cooking and fashion sense she is a decent person. Her sister who likes annoying her is Aunt Carol. She is portrayed by Maddie Corman in the film. Jamie's father is generally a gross person as well as boring (at least according to Jamie). He can never get names right and constantly calls Stinker "Jamie" and vice versa. He also calls Isabella "Isadora" and Angeline "Angela" despite being corrected multiple times. He is portrayed by Jeffrey Hanson in the film. Stinkette is one of a litter of four puppies whose parents are Stinker and Angeline's dog Stickybuns. Jamie adopts her due to her resemblance and attachment to her father. Hudson Rivers is a boy who both Jamie and Angeline have a crush on despite Hudson being said to be the "eighth cutest boy in the school". He is shown as having crushes on both Jamie and Angeline, but neither of them as big as his crush on Isabella, who he asks out to have tacos with him after the school dance in Never Underestimate Your Own Dumbness, but she tells him she couldn't come as she was being punished for fake-falling down the stairs. He asks out Jamie and Angeline, but they ultimately decline his offer, believing that he rejected Isabella when he told them she couldn't come. He is portrayed by David Mazouz in the film. Mike Pinsetti or Antonio Michael Pinsetti, more frequently known simply as Pinsetti, is an unpleasant bully character, described as a "human sack of turds", who likes making poorly-thought-up nicknames for every student in the school. He is somewhat afraid of Angeline, who punched him when he called her "big weird thing", as was revealed in the book Dear Dumb Diary Deluxe: Dumbness Is A Dish Best Served Cold. He has a crush on Jamie which she justifiably rejects. Generally known for disgusting habits and poor hygiene, after meeting the substitute lunchroom monitor Sebastian Bruntford in The Super-Nice Are Super-Annoying, he attempts to mend his reputation by becoming well-mannered and polite, wearing ties and suggesting a fancy dance party. He is portrayed by Carson Oliver in the film. Colette is a girl from Wodehouse Middle School who was constantly bullied due to various incidents (in particular one where she laughed so hard while eating spaghetti that it shot out of her nose and the school nurses tried to see if it was a vein or intestine while the "whole world of her school" watched) and as result she has no friends. As revenge she placed rotting cat food in her school's ventilation causing the school to be shut down temporarily. During that period, she is transferred to Mackerel Middle School where she befriends Isabella, Jamie and Angeline, while the school handed out ballots so students could vote for each other in categories such as prettiest, most artistic, funniest etc. Colette seems to be highly competitive with Angeline who is only ever voted Prettiest each year, using makeup to make herself even more beautiful so as to be voted for Prettiest in order to save her reputation, resulting in Angeline writing "VOTE JAMIE FOR PRETTIEST" on the bathroom walls to have Jamie steal votes so Angeline can stay as Prettiest as she "wasn't about to lose her one lame category". After discovering Colette's tragic backstory, Isabella persuades Colette, Angeline and Jamie to agree to her plan, presumably involving switching the ballots for Colette's title of Most Clever into Prettiest, leading to Colette winning the vote and saving her reputation. Miss Bruntford is the school's cafeteria monitor who forces everyone to eat the school's disgusting meatloaf on Thursdays. She is very accident prone due to her obesity combined with her tiny high-heeled shoes. Jamie often jokes about her fatness, even stating she could have her own planetary orbit. In the book Am I The Princess or the Frog? she eats her own meatloaf and faints while yelling, "Call 911!" While Bruntford recovers, Jamie's mother is called on to be the acting cafeteria monitor but her meatloaf is far worse, and this is believed to be a set-up by Bruntford to make her own meatloaf look better by comparison. She becomes Isabella's co-conspirator in the attempt to stop Ms. Anderson from coming to Devon and Carol's engagement announcement party. In The Super-Nice Are Super-Annoying she is revealed to be rather wealthy, living in a lavishly decorated mansion with her son Sebastian. Her now-deceased husband was the previous cafeteria monitor. In Nobody's Perfect. I'm As Close As It Gets, it is revealed that the school had been buying cheap meatloaf to save money for high-quality ground coffee at the teachers' lounge, this being a conspiracy orchestrated by Bruntford and science teacher Mrs. Curie. When Jamie reveals to the whole school staff how terrible the meatloaf is, Thursday is no longer meatloaf day, but rather "surprise day", where Bruntford goes around asking for feedback on her new improvised food (though it is no less cheap and poorly-thought-out). She is portrayed by Lea DeLaria in the film. Sebastian Bruntford is Miss Bruntford's son who takes over her cafeteria monitor duties in The Super-Nice Are Super-Annoying. He is a handsome and polite young man who Jamie and Isabella attempt to romance when he talks with them and Angeline during lunch, using their school assignment about manners as an excuse to charm him. In contrast, Angeline deliberately acts mean when Sebastian is around, due to her not wanting to be seen as merely a "delicate and well mannered creature of grace" (a phrase that Sebastian used to refer to a popular actress before Jamie used it to refer to herself in an attempt to flirt with him). Despite attempting to romance him for his wealth, Isabella abandons Sebastian upon discovering that if she married him, she would become Miss Bruntford's daughter in law.