|Relatives|| Quincy Barrett (father)|
Tanya Barrett (mother)
Elizabeth "Betty" Barrett (also known as Atomic Betty) is the show's main protagonist (voiced by Canadian actress and singer Tajja Isen).
On her home planet Earth, and to most of her friends and family in her hometown of Moose Jaw Heights, young Betty Barrett is a typical average yet cute and tomboyishly beautiful 6th Grade pre-teen middle schoolgirl who is highly athletic and loves almost every single sport that she tries, especially ice hockey.
She enjoys visiting her grandmother Bea on her farm, which is located outside of Moose Jaw Heights, singing with her friends in her band, goofing off, hanging out with her best friends and daydreaming about living in outer space. She is not afraid to speak her mind on any subject, and she dislikes any and all forms of bullying, snobbery, and injustice.
However, when there is trouble in outer space, she is called on by her friend and her commanding officer, Admiral DeGill, and along with her crew, is the captain of her own Starcruiser under her secret identity of Atomic Betty, who is revered throughout the galaxy as a well-known and quite famous Galactic Guardian and Defender of the Cosmos.
When in outer space, she and her crew, a food loving, green skinned alien pilot named Sparky and her robotic navigator and second-in-command named X-5, investigate various intergalactic crimes and fights evil super-villains. An expert hand-to-hand fighter, she can easily defend herself against most opponents, but is also equipped with a special Galactic Guardian issued utility bracelet, which houses various technological devices, such as a holographic communicator she uses to speak to Admiral DeGill, her commanding officer and her crew, and remote controls for her starcruiser and its teleporter, as well as an array of gadgetry and weaponry to use on her missions.
In the first season of Atomic Betty, Betty at first thought that she was the only human ever to be chosen to be a Galactic Guardian, until she discovered her Grandmother Bea was a retired Galactic Guardian named Beatrixo, and also one of the first Galactic Guardians.
Betty has red hair, usually worn in a pony tail, and emerald green eyes. When she is on Earth, she wears her usual outfit worn on her body during the show itself consists of her green headband, her yellow sweater with a white shirt underneath, her green knee-length short skirt, white knee-high length athletic sport socks, and black-and-white athletic sneakers.
When on a mission for action, she wears her standard Galactic Guardian uniform, which consists of her white head-dress, pink dress, white gloves, pink bracelet, white belt with a nuclear symbol, and white thigh-high boots.
Betty is a very beautiful, smart, cute, friendly, funny, strong willed, charming and very independent young girl with highly eccentric interests, and is not afraid to speak her mind on any subject. Despite her cuteness and beauty, she also has a bit of a temper, and can get easily annoyed, most often by her rival Penelope Lang.
On Earth, she likes playing pranks, listening to music, reading her science fiction comics, popping an Ollie on her skateboard, hanging with her best friends Noah and Paloma, or daydreaming about her crush, Dylan.
In space, she loves protecting the galaxy with her crew, flying in her starcruiser and karate chopping treacherous galactic super-villains. In the episode Attack Of The Evil Baby, Betty was afraid to get her tooth out when she went to the dentist with her mother.
Betty has no superpowers, but she is exceptionally strong and agile for a twelve-year-old girl despite her beauty and has a good knowledge of galactic combat techniques, as she's been seen being able to take down much larger alien opponents with one punch. She is also a very capable Galactic Guardian captain and a very good leader, though at times she can be a bit bossy to her crew, and has shown exceptional prowess in sports, including both skateboarding and surfing.
She is shown to have some slight mystical abilities in the episode Spindly Tam Kanushu, where she uses a special meditation technique to locate the exact planet that her alien martial arts master, Spindly Tam Kanushu, has been taken to by Maximus.
- Tanya Barrett - mother, also Purrsy's owner
- Quincy Barrett - father, also Purrsy's owner
- Purrsy - pet cat
- Sparky - friend and ship's pilot
- X-5 - robotic friend and ship's navigator
- Miss Dourly - art teacher, English teacher and history teacher
- Admiral DeGill - commanding officer
- Noah Parker - best male friend and secret love admirer
- Beatrixo - grandmother
- Jimmy - grandfather
- Principal Peterson - principal
- Paloma - best female friend
- Osborne Twins (Chip and Dalton) - friends
- Penelope Lang - rival, also spoiled brat
- Dylan - crush
- Maximus I.Q. - nemesis
- Minimus P.U. - nemesis
- Spindly Tam Kanushu - martial arts teacher
- The Betty Clones - clones
- Despite her human appearance, she is an alien/human hybrid and her homeplanet is Bane of Fragnog.
- Betty is not a very good detective because she saw some clues of her grandmother Beatrixo being a Galactic Guardian and her friend Paloma is an alien, but she didn't think there true despite the fact that most people on Earth don't believe aliens are real.