Main characters • Numbuh 1/Nigel Uno (voiced by
Benjamin Diskin) - The leader and head operative of Sector V as well as the only child of Monty Uno. • Numbuh 2/Hogarth Pennywhistle "Hoagie" Gilligan, Jr. (voiced by Benjamin Diskin) - The best friend of Numbuh 1, the joke-cracking engineer and 2x4 Technology Officer of Sector V as well as the older brother of Tommy Gilligan. • Numbuh 3/Kuki Sanban (voiced by
Lauren Tom) - The happy-go-lucky tactician and medic of Sector V as well as the older sister of Mushi Sanban. • Numbuh 4/Wallabee "Wally" Beetles (voiced by
Dee Bradley Baker) - The brash combatant of Sector V as well as the older brother of Joey Beetles. • Numbuh 5/Abigail "Abby" Lincoln (voiced by
Cree Summer) - The intelligent, relaxed
second-in-command/spy of Sector V and the younger sister of Cree Lincoln. Numbuh 5 speaks in an
illeism.
KND Organization • Numbuh 6/Bradley (vocal effects provided by
Dee Bradley Baker) - A
striped skunk who became an honorary member of Sector V after Hoagie and Kuki saved him in the streets. In "Operation: H.O.S.P.I.T.A.L.", Bradley is converted into a cyborg to save his life after he is hit by a car. • Numbuh 9/Maurice (voiced by
Khary Payton) - A former member of Sector V who was reinstated to the Teens Next Door, a special operations group that fake being decommissioned on their 13th birthday, so they can learn information from both adults and teenagers. • Numbuh 13 (voiced by
Billy West) - The Klutz of the KND. While he means well, he is ignorant to the fact that he is incredibly clumsy, klutzy, and moronic. Like the KND's Toiletnator, every sector dreads having to work with him, even his own. The Sector Leader of N, Numbuh 14/Mary-Lou Sara-Jane Jones (voiced by Lauren Tom), has the literal job of being his damage control, which she resents very much. • Numbuh 60/Patton Drilovsky (voiced by Matt Levin) - A high-ranking operative of the Kids Next Door Arctic Base. • Numbuh 65.3/Herbie (voiced by
Dee Bradley Baker) - The stuffy and nerdy Head Communications Officer of Moonbase. He often hails Sector V for urgent missions. He is also fond of Lizzie Devine. • Numbuh 83/Sonia (voiced by
Janice Kawaye) - The Soda, Snacks, and Treats officer of Sector W, she has an irrational fear of the dark and will go into a blind rage when she is forced towards it. • Numbuh 84/Lee (voiced by Janice Kawaye) - The tactical Yo-yo Specialist of Sector W. • Numbuh 86/Fanny Fulbright (voiced by
Jennifer Hale) - The Head of Decommissioning and Global Tactical Officer of the KND Organization. She is a bossy girl and speaks with an Irish accent. • Numbuh 92 and Numbuh 93 (voiced by Benjamin Diskin and
Tara Strong) - Two KND operatives who reside on the Kids Next Door Moonbase. Their roles are effectively replaced with Numbuh 44/Pete and Peter Doblemitz (voiced by
Lauren Tom), twin operatives who also work as infantry. • Numbuh 101/Matt (voiced by
Ogie Banks) - The Head of the KND Seriously Cool Museum of Artifacts and Stuff. He is a mega fan of Sector V and an avid KND history enthusiast, believing in Sector Z and Numbuh 0 even when others thought that they were just myths. • Numbuh 362/Rachel McKenzie (voiced by
Rachael MacFarlane) - The Supreme Leader of the KND Organization. • Numbuh 363/Harvey McKenzie (voiced by
Jennifer Hale) - The sector leader of Sector W, and Numbuh 362's younger brother. He is rivaling with Sector V in the series finale, who do not like him due to his cockiness and dislike of being touched by others. He was decommissioned months later by Numbuh 5 because she got sick of him not wanting to be touched. • Numbuh 74.239 and Numbuh Infinity (voiced by
Dave Wittenberg and
Phil LaMarr respectively) - Two KND operatives who worked for the Splinter Cell, a shadowy faction of the Kids Next Door. They have manipulated events to sign Nigel to the Galactic KND.
Villains • Father/Benedict Wigglestein-Uno (voiced by
Maurice LaMarche when suited,
Jeff Bennett when unsuited) - The arch-nemesis of the KND, the main antagonist of the series, and the "adoptive" father of the Delightful Children From Down the Lane. He is also Nigel's paternal uncle and Monty's brother. Father wears a silhouetted suit and possesses
pyrokinesis. In "Operation: Z.E.R.O.", it is revealed that Father kidnapped the members of Sector Z and brainwashed them to become the Delightful Children. • The Delightful Children From Down the Lane (voiced by
Benjamin Diskin,
Dee Bradley Baker, and
Cree Summer in unison, and by
Tom Kenny,
Rachael MacFarlane,
Jason Harris,
Dee Bradley Baker, and
Cree Summer individually as Sector Z), five 'delightfulized' kids, and Father's children who serve as the secondary antagonists of the series. In "Operation: Z.E.R.O.", they are revealed to be the former members of the missing Sector Z; Bruce (blonde boy with bowl cut), Alessandra (brunette-blond haired girl), David (tall, skinny boy with a comb-over), Lenny (black boy with a football helmet), and Constance (fat girl with brown hair and pigtails), (clockwise from the front). "Delightfulization" is shown to be a form of brainwashing throughout the series, with Sector Z's brainwashing being permanent. As a result, any attempt to reverse it can only be temporary. • Jenkins (voiced by
Dee Bradley Baker) - The elderly butler of the Delightful Children From Down the Lane. • The Teen Ninjas - A group of teenagers in Battle Ready Armor who often work for Father or the Delightful Children From Down the Lane. • The Steve (voiced by
Jeff Bennett) - The leader of the Teen Ninjas. • Cree Lincoln (voiced by
Cree Summer) - Numbuh 5's older sister, field leader of the Teen Ninjas, and an apprentice to Father. She was originally a KND operative Numbuh 11. While a dangerous foe, Cree does care about her sister and wished that Numbuh 5 joined the teens just like her. • Chad Dickson (voiced by
Jason Harris) - Formerly Numbuh 274, Chad was the supreme leader of the Kids Next Door until it was revealed in "Operation: E.N.D." that he had hidden his thirteenth birthday to the KND and arranged Sector V's decommissioning. Due to his treason, he allies with the adults and joined the Teen Ninjas. In "Operation: T.R.E.A.T.Y.", it is revealed that he is a TND operative working for the Splinter Cell. • Mr. Boss (voiced by
Jeff Bennett) - A corporate
businessman, the
CEO of Werk Co and the de facto second-in-command of the KND's enemies. In "Operation: D.A.D.D.Y.", it is revealed that he is Numbuh 86's father. • Mr. John Wink and Mr. Timothy Fibb (voiced by
Tom Kenny and
Dee Bradley Baker respectively) - A pair of villains who use robotic chairs to fight. In "Operation C.O.W.G.I.R.L.", is it revealed that Wink and Fibb were members of Cowboys Kids Club and became villains after fellow Cowboy Kids Club member Lasso Lass went the prom with Texas Tommy instead of Timothy. They are a parody of
Mr. Wint and Mr. Kidd and address each other in the same manner. • Laura Limpin / The Big Badolescent (voiced by
Grey DeLisle in normal form,
Dee Bradley Baker in teen form) - A little girl who, while normally is innocent and thus does not have the personality of a villain, has a "condition" that turns her into a hulking monster when she gets angry. She is a parody of
Hulk. • The Toiletnator/Lou Pottingsworth III (voiced by
Dee Bradley Baker) - A toilet-themed incompetent villain, being considered the lamest villain by the KND and by other villains. In a comic spin-off, it is revealed that he is Wally's long-lost uncle. • Stickybeard (voiced by
Mark Hamill) - The candy-loving pirate captain of the Candy Pirates and a rival of Numbuh 5's due to their mutual obsession with sugar. He uses a pirate ship called the Sweet Revenge as his mode of transportation on air, land, and sea. Despite being sour towards the Kids Next Door, he does show a "sweet tooth" such as saving Sector V from the Great White
Asparagus (which he loathes more than kids) in "Operation: A.F.L.O.A.T." and helping Numbuh 5 save Heinrich from cursed licorice pirates. • Chewy and Gooey (voiced by
Dee Bradley Baker and
Daran Norris) - Two
cabin boys of the Candy Pirates who are often seen with Stickybeard. They respectively wear red and blue bandanas. • Dumb John Silver (voiced by
Daran Norris) - An unintelligent helmsman working on the Sweet Revenge. • Knightbrace/Mr. Jelly (voiced by
Tom Kenny) - An oral health-themed vigilante who performs painful and unnecessary dental and orthodontic procedures on the children he ambushes. As a civilian, he is the former owner of a candy shop the KND frequently visit. Mr. Jelly intended to be a dentist since he was a child, but was expelled from dental school for attempting to put braces on babies. He was forced to work in his family's candy store, but later became Knightbrace due to being angered at candy harming children's teeth. • The Common Cold (voiced by
Tom Kenny) - A sickness-based villain who uses his own snot to render all KND operatives sick so they'll be too weak on stopping other adults' plans. He has a niece named Anna Worthington (his sister-in-law's daughter). • The Parent Teacher Organization of Eradicating Youngsters (PTOOEY) - A group of parents and teachers who want to rule the world with no involvement from children. • Peter Principal (voiced by
Tom Kenny) - A principal with flight and the leader of PTOOEY. • Mad Dad (voiced by
Jeff Bennett) - An abusive father in a tank top, tie, boxing gloves, boxers, and slippers who would take out his anger of bad grades on others. • Terrible Tutor (voiced by
Dee Bradley Baker) - A tutor who can fly and shoot textbooks out of the sleeves of his graduate robe. • Midwestern Mom (voiced by
Grey DeLisle) - A mother who is an expert wrestler. • Heli-Teacher (voiced by
Cree Summer) - An old teacher who can fly around on a chair that has a helicopter propeller on it. • Gramma Stuffum (voiced by
Grey DeLisle) - An old lady obsessed with force-feeding disgusting food to children to make them unable to move so that they cannot bother adults. • Food Army - The food creations of Gramma Stuffum. • Liver and Onions - A liver and two giggling onions who are members of Gramma Stuffum's Food Army. • Count Spankulot (voiced by
Daran Norris) - A
vampire vigilante who spanks naughty children. Like the Toiletnator, he wants to join a group but his spank addiction always gets him rejected. In "Operation: L.O.C.K.D.O.W.N.", he demonstrated the ability to turn people into spank-happy vampires. • The Proper Patrol - A militaristic duo who use jetpacks as their mode of transportation. They often goes around trying to dress up children in proper clothing. • Major Mrs. Manners (voiced by
Jennifer Hale) - A member of the Proper Patrol. • Sergeant Sensible (voiced by
Daran Norris) - A member of the Proper Patrol. • Crazy Old Cat Lady (voiced by
Grey DeLisle) - An old woman with cat-like features who lives with thousands of black and white cats. • Professor XXXL (voiced by
Frank Welker) - A scientist who wants to create the most perfect snow cone that has ever been made. Every time he appears, he has different animalistic parts in his body. • Professor Bob (voiced by
Dee Bradley Baker) - A mad scientist who wants to end snow days. • Chester (voiced by
Tom Kenny) - A greedy man who wants to make money at the expense of children. • Mr. Mogul (voiced by
Rob Paulsen in "Operation: R.A.I.N.B.O.W.S.",
Dee Bradley Baker in "Operation M.O.V.I.E.") - The CEO of Rainbow Monkeys Inc. • Simon (voiced by
Tom Kane) - The personal assistant of Mr. Mogul. • Mega Mom and Destructo Dad / Mrs. and Mr. Dickson (voiced by
Grey DeLisle and
Jeff Bennett) - Numbuh 274's parents, who intended their son to be the best by petrifying the other KND operatives. • Mr. Fizz (voiced by
Jeff Bennett) - A businessman who is the head of the Soda Control Board who "legalize" the age of when children should not drink root beer. He cannot stand the sound of children and often drinks soda to soothe his nerves. • Lieutenant Seltzer (voiced by
Greg Cipes) - A teenage intern and field commander of the Soda Control Board. • Big Brother (voiced by
John DiMaggio in "Operation: M.I.N.I.G.O.L.F.",
Daran Norris in "Operation: M.O.V.I.E.") - A giant-size teenager. • The Great Puttinski / Rupert Puttkin (voiced by
Rob Paulsen) - An arrogant and rude miniature golf champion who takes the sport very seriously. • Senior Citizen Squad - A group of senior citizens residing at Sure Would Forest Retirement Home. They often make use of an anti-aging cream that temporarily turns them into teenagers. The Senior Citizen Squad can also use their elderly equipment to form one giant robot called the "Senior Citizen". • Lydia Gilligan (voiced by
Candi Milo) is Hoagie's grandmother and leader of the Senior Citizen Squad. In her teenage form, her walking stick can be used as a melee weapon. • Sheldon (voiced by
Tom Kenny) is a member of the Senior Citizen Squad. In his teenage form, Sheldon's walker acts as wings. • Maurice (voiced by
Dee Bradley Baker) is a member of the Senior Citizen Squad. In his teenage form, Maurice uses his wheelchair wheels as weapons. • Ice Cream Men (variously voiced by
Dee Bradley Baker,
Tom Kenny,
Daran Norris, and
Kevin Michael Richardson) - The Ice Cream Men are ice cream vendors who operate Ice Cream Trucks and only serve ice cream to adults. • Elite Ice Cream Men (variously voiced by
Jess Harnell,
Maurice LaMarche, Matt Levin,
Daran Norris, and
Khary Payton) - A version of the Ice Cream Men who wear ice cream cone-themed armor. • Chef Pierre (voiced by
Jess Harnell) - An Elite Ice Cream Man and cake chef who was once commissioned by Father to build a giant ice cream cake. • Mrs. Goodwall (voiced by
Candi Milo) - A zoologist with a lion-like tail. • Cheese Shogun Roquefort (voiced by
Kevin Michael Richardson in "Operation: T.H.E.-S.H.O.G.U.N.",
Fred Tatasciore in "Operation: I.N.T.E.R.V.I.E.W.S.") - The
shogun of the Cheese Empire. • Cheese Ninjas (voiced by
Daran Norris and
Kevin Michael Richardson) - A group of ninjas who are the minions of Cheese Shogun Roquefort. • Cheese Ninja Leader (voiced by
Brian Tochi) - The leader of the Cheese Ninjas. • King Sandy (voiced by
James Arnold Taylor) - An average little kid who portrays himself as a tyrannical king and hates being told that he is only pretending. • The Knights of the Round Towel (voiced by
Jeff Bennett and
James Arnold Taylor) - The teenage cousins of King Sandy who are loyal to him. • Cuppa Joe (voiced by
Tom Kenny) - The proprietor of a coffee rig that gets high on coffee. • Coffee Workers (voiced by
Jason Harris and Tom Kenny) - Coffee rig workers who work for Cuppa Joe. • Mr. Washer (voiced by
Rob Paulsen) - A hobby store proprietor who once paired Hoagie and The Kid against each other. • The Interesting Twins From Beneath The Mountain - Two Japanese twins consisting of an unnamed boy (voiced by
Tom Kenny) and an unnamed girl (voiced by
Tara Strong) who worked for Father, with facepaint similar to the
Yin and Yang symbol. Although the two are masters of disguise and espionage, they tend to suffer a lot of misfortunes and setbacks. • The Six-Gum Gang - A gang of child robbers who worked for the Delightful Children From Down the Lane to steal other children's homework and pass it off as their own. • Runt (voiced by
Jennifer Hale) - A member of the Six-Gum Gang whose hat goes over his eyes. • Lunk (voiced by
Dee Bradley Baker) - A member of the Six-Gum Gang. • Goof (voiced by
Tom Kenny) - A member of the Six-Gum Gang. • Wilbur (voiced by
Benjamin Diskin) - A member of the Six-Gum Gang. • Dixie (voiced by
Jennifer Hale) - A member of the Six-Gum Gang. • Nurse Claiborne (voiced by
Jennifer Hale) - A school nurse. • Henrietta "Heinrich" Von Marzipan (voiced by
Dee Bradley Baker while cursed,
Candi Milo while uncursed), Numbuh 5's arch-rival, who travels the world in search of rare candy and will often go to villainous extremes to get it. She hates Numbuh 5 for an unknown past event in Guatemala, eventually explained in "Operation: C.A.R.A.M.E.L.". It is revealed that she is actually female and was cursed into a male form. Heinrich and Abigail reconcile after her curse is lifted. • Candy Bandits (voiced by
Rob Paulsen and
Cree Summer) - A group of mercenaries who worked for Heinrich in "Operation: J.E.W.E.L.S." and "Operation: R.A.B.B.I.T." • James Nixon McGarfield (voiced by
Tom Kenny) - McGarfield was the Fourth Grade President-for-life of Gallagher Elementary until it was revealed that he allied with Father. His name is a reference to American presidents who were involved in scandals and disasters:
Richard Nixon,
William McKinley,
James A. Garfield, and
James Buchanan. • Anna Worthington (voiced by
Anndi McAfee) - McGarfield's personal assistant who is the niece of the Common Cold. • Honor Roll Nerds (voiced by
Benjamin Diskin and
Tom Kenny) - The textbook-wearing minions of McGarfield. • Ernest (voiced by
Dave Wittenberg) - Ernest is the leader of the bullies who commissions underground sports involving kids to misbehave. His name is a reference to
Ernest Hemingway, who was a fan of Spanish Bullfighting. • Soccer Mom (voiced by
Grey DeLisle) - An abusive motherly soccer coach. Her name is a spoof of the "
soccer mom" archetype. • Robin Food (voiced by
Rob Paulsen) - A cafeteria worker at Sure Would Forest Retirement Home who steals food from the home to use for himself, reasoning that the residents are unable to eat the food themselves. He is a parody of
Robin Hood. • Little Juan (voiced by
Roger Rose) - A cafeteria worker at Sure Would Forest Retirement Home who is Robin Food's right-hand man. He is a parody of
Little John. • The Hungry Men (variously voiced by
Dee Bradley Baker and
Tom Kenny) - The minions of Robin Hood. They are a parody of the
Merry Men. • Bag-Headed Cashier (voiced by
Dee Bradley Baker) - A cashier in a paper grocery bag mask who works at the Supervillains Supermarket & Deli. • Dodgeball Wizard (voiced by
Dave Wittenberg) - A wizard who is out to prove that adults that can play dodgeball too. • Teen Tornado - A teenage villain who can spin around in a tornado. • Potty Mouth (voiced by
Maurice LaMarche) - A toilet-headed villain. • Grandfather (voiced by
Neil Ross) - Monty and Benedict's father who is the main
antagonist in "Operation: Z.E.R.O.". His main goal was to turn all children and adults into obedient elderly zombies to reclaim domination across the world. Grandfather is defeated by the recommissioned Numbuh 0, who erases both of their memories using the Decommissioning Chamber. In addition, there are also some unnamed villains who made background appearances at villain gatherings: • A clown villain. • A hammer-handed villain with the words "no" on the bottom of the hammers and has NG on the chest of his outfit. • A lightbulb-headed villain. • A spacesuit-wearing villain. • A villain in an iguana suit. • A villain in a sheep costume who resembles the titular character from
Sheep in the Big City. • A villain with a large exposed brain. • A villain with a large smoking pipe made of industrial pipes.
Other characters • Lizzie Devine (voiced by
Grey DeLisle) - Nigel's girlfriend and then later ex-girlfriend; they broke up at the end of the season 6 episode, "Operation: G.I.R.L.F.R.I.E.N.D.". While they were together, she was extremely possessive of him and was always looking to spend as much time with him as possible, which inconveniences him if he was in the middle of KND business. • Numbuh 0/Montgomery "Monty" Uno (voiced by
Frank Welker as an adult,
Dave Wittenberg as a child) - Nigel's father. He is later revealed to have started the Seventh Age of the KND after defeating Grandfather as Numbuh 0. • Mrs. Uno (voiced by
Jennifer Hale) - Numbuh 1's mother and Father's sister-in-law. In "Operation: I.N.T.E.R.V.I.E.W.S.", it is revealed that she was originally a KND operative Numbuh 999, and was the first female operative of the Seventh Age. • Betty Gilligan (voiced by
Candi Milo) - Numbuh 2's mother. • Thomas "Tommy" Gilligan (voiced by
Dee Bradley Baker) - Hoagie's baby brother who constantly wanted to join Sector V on their missions, much to their annoyance. In "Operation: G.R.A.D.U.A.T.E.S.", he temporarily becomes a KND operative "Numbuh T" until he resigns himself from the code module in order to stop one of Father's plans, and becomes a vigilante known as "The Tommy". • Kani Sanban (voiced by
Keone Young) - Kuki's father. While high strung and moody, he does love his children. His name means "crab" in Japanese, fitting his crabby personality. • Genki Sanban (voiced by
Lauren Tom) - Kuki's mother. She is a successful businesswoman and is the boss of Betty Gilligan. While she never played with toys as a girl, she does let her daughters have toys as to give them a happy childhood unlike her. • Mushi Sanban (voiced by
Tara Strong), Numbuh 3's little sister. In season 4, she becomes a villain after "murdering" her sister's new Rainbow Monkey out of jealousy. Mushi kidnaps Count Spankulot to create Spankenstine as revenge towards Numbuh 2. • Sydney Beetles (voiced by
Jeff Bennett) - Wally's father. • Mrs. Beetles (voiced by
Jennifer Hale) - Wally's mother. • Joey Beetles (vocal effects provided by
Dee Bradley Baker) - Wally's baby brother. He is surprisingly powerful and witty for being only a baby, defeating multiple villains. • Dr. Lincoln (voiced by
Kevin Michael Richardson) - Abigail's father. He used to work as a clown until his co-worker messed up his joke, ruining their careers. • Mrs. Lincoln (voiced by
Cree Summer) - Numbuh 5's mother. ==Episodes==