Judith "Judy" Neutron is a major character in the franchise.
Judy is head of the Neutron household. She's no-nonsense, but always concerned with Jimmy's exploits and how his day went. Taking a cue from Martha Stewart, Judy has perfectly coiffed hair and is always attired in a wrinkle-free dress. But though she typically wears an apron, it's not for working in the kitchen. Instead, she can frequently be found adding performance modifications to the family car.
Judy is a tall and skinny 50's housewife style woman. She has brown hair in a 50's flip hairstyle and green eyes with pale green eye shadow. She wears large gold hoop earrings and a white pearl necklace along with light pink lipstick. She also wears a green sleeveless dress with small pink polka dots and green high-heel dress shoes. She has a beauty mark on the left side of her face. Her nails are polished with pink nail polish. In Jimmy Neutron: Boy Genius and Pilot, she sometimes wears a white apron.
Judy is a caring and loving mother towards Jimmy, and is very affectionate towards her husband, Hugh. However, she gets frustrated with Jimmy's antics and all the trouble he causes, usually having to give him a lecture or put him in his place. For example, In When Pants Attack, we find out that Judy has asked Jimmy to pick up his pants 54 separate times to no avail. She often makes Jimmy do chores before performing an experiment or going to space. This usually causes Jimmy to find creative ways around his chores, leading to much bigger problems, such as the invention of the Jimmy's clones and the Maternotron.
Sometimes, it is hinted that Jimmy may have gotten his super intelligence from his mother. One example of this occurs in See Jimmy Run, where she scientifically points out a flaw in Jimmy’s Shoebot that he hadn't considered. Another example takes place in Maternotron Knows Best, where she impresses Jimmy by pulling a highly advanced molecular blasting ray out of her utility closet to shut down the Maternotron. She also put a tracking device in Hugh's skin, revealed in Aaughh!! Wilderness!!, to make sure he stays safe. Additionally, Judy is the family mechanic. She can often be found in the garage, checking the plugs and points or adding horsepower to the family roadster.
She is obsessed with cleaning, and is a bit of a germophobe. She goes through great lengths to ensure that the Neutron household remains clean, including dusting the lawn, as seen in Crime Sheen Investigation. In the same episode, she admits that she wanted to throw Sheen's Ultra Lord away after seeing how filthy it was, but couldn't because she didn't have her rubber gloves with her.
She loves cooking and baking, especially pies. She often makes fresh pies for Hugh, much to his delight. In Make Room for Daddy-O, Judy begins panicking when Hugh rejects one of her pies, theorizing that he may now be into cakes or tarts now. She often uses uncommon ingredients, such as when she makes a brambleberry pie for the Wheezer family in The Feud.
- "I am never leaving you two alone again! Humph!" -My Son, the Hamster
- "Hugh, do you ever realize that a lot of the things you say make NO sense??" -The League of Villains
- "But wouldn't the combustion cycle become increasingly irregular due to the inhibiting effects of the silicon's thermal resistance?" -See Jimmy Run
- "Hugh Neutron, you buy our son back this instant!!" -Birth of a Salesman
- "Chores first! Space travel later." -Send in the Clones
- "Hugh that was not our son! That thing had fur with big teeth and whiskers!" -My Son, the Hamster
- "Hugh that's Poultra's water dish!" -The Eggpire Strikes Back
- "Not Pizza Clown too!" -Men at Work
- "Hi boys, there are fudge nellies in the kitchen." -Crime Sheen Investigation
- "Jimmy, I never want to hear you say the word Carl again!" -The Feud
- "Jimmy! My sweet baby! What is he doing there!?" -Win Lose and Kaboom!
- "Cindy, Libby, have some cake and goody bags!" -Hypno-Birthday To You
- "James Neutron, go to bed right now, and I mean you! Not the Jimmy Android that says nice things!" -Krunch Time
- "Hugh, you can't just invent a new holiday." -Holly Jolly Jimmy
- "This is serious! Maybe he's a cake man now, or tarts, oh goodness! It's off to the kitchen with me, oh!" -Make Room for Daddy-O
- "Don't be silly young man, I would never have a child as dim-witted as you!" -I Dream of Jimmy
- "What a wonderful costume! But I thought you were going be the Duck Man of La Mancha." -Nightmare in Retroville
- "Sweetie relax, I just had to put your father in there to keep him from annoying the townspeople." -Sorry, Wrong Era
- "Hugh, you promised me you wouldn't spend the grocery money on any of your hobbies!" -Attack of the Twonkies
- "Jimmy, I know you're innocent, don't forget to brush your teeth. Hugh, our little boy is going to jail!" -Who Framed Jimmy Neutron?
- Judy's catchphrase is "James Isaac Neutron!"
- Judy is hypnotized by the Hypno-beam three times, in Hypno-Birthday To You, The Trouble with Clones, and the Jimmy Timmy Power Hour.
- In Maternotron Knows Best, she is shown to be quite skilled at fighting.
- In The Jerkinators, Mr. Turner tells her that she has a mole on her ankle.