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 tomboyishly beautiful pre-teen schoolgirl who is highly athletic and loves almost every single sport that she tries, especially ice hockey. Betty Barrett is also a human/alien hybrid.
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, and hanging out with her best friends. 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 as a 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.
All three seasons of Atomic Betty have yet to tell us exactly how and at what age Betty was recruited to join the Galactic Guardians. However, some episodes have showed Betty training with her martial arts master, Spindly Tam Kanushu when she was younger in his birthplanet, Bane of Fragnog.
Also, 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.
Siblings of Paloma
She also believed that Paloma and Juanita were siblings and human, and she first thought Paloma's knowledge of aliens were just a coincidence because she seemed to be normal and Betty is just a young child and she doesn't know any better, until Betty learned the hard way about Paloma's past and realized that her knowledge of aliens was due to experience and Juanita is really a Galactic Guardian assigned to protect her.
Betty tried to get answers from Juanita about who Paloma is and why she was on Earth, and wanted to know when Juanita became a Galactic Guardian, but Juanita and Paloma left Earth before she got a chance to learn any more from them.
Betty was the only one of her friends and her crew to object to Admiral DeGill's decision to have Galactic Guardian Headquarters rebuilt on Earth after its destruction, and for headquarters to be built underneath her home town of Moose Jaw Heights, having preferred DeGill building the headquarters on another planet (or even a different, isolated location on Earth, such as the North Pole or a desert island).
In the third season, Mission: Earth, she has become a bit more commanding in her duties as a Galactic Guardian captain, due to the stress involved with Galactic Guardian Headquarters having moved to under her home town, the increased involvement of her crew members and other space friends in her daily life, her budding romance with Penelope Lang's older brother Chaz Lang, and the fact that since Galactic Guardian Headquarters has been relocated to Earth, an increasing number of intergalactic supervillains have targeted her home planet, Earth, as well as trying to hide her secret identity and the new Galactic Guardian Headquarters from most of her family and friends in Moosejaw Heights. The reason she keeps her Galactic Guardian identity a secret from her family and friends is to protect them and Earth. If anyone finds out about this, Maximus will find out as well and he'll destroy her planet. Another reason for her keeping her Galactic Guardian identity a secret from her friends and family, is that when in space, she is famous as the Universe's best loved protector and Earth is the only place for her to have a somewhat normal life.
Betty has a red hair, usually worn in a pony tail, and emerald green eyes. When she is on earth for comedy, 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 socks, and black-and-white sneakers. In the show's newly-upcoming revival onward, her new usual outfit worn on her body consists of her yellow short-sleeve tee shirt with green highlights and a big green nuclear symbol on the center and her blue long-leg full-length slacks with light blue cuffs on bottom, but the rest of her original usual outfit from the show itself can still be worn on her body.
When on a mission for action, she wears her standard Galactic Guardian uniform, which consists of her white head-dress, red lipstick, pink dress, white gloves, pink bracelet, white belt with a nuclear symbol, and white thigh-high boots.
Betty is smart, cute, friendly, funny, strong willed tomboy, charming, and is a very independent young girl with highly eccentric interests, and is not afraid to speak her mind on any subject. She also has a bit of a temper, and can get easily annoyed, which shows during certain moments, such as in the episode Shake Your Booga, when she was called for a mission during a party, and imagined yelling at DeGill that Chaz asked her to dance.
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, Regeena, and Paloma or daydreaming about her crush, Chaz.
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, 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.
Atomic Betty: Mission: Earth
During the third season of Atomic Betty, which was retitled as Atomic Betty: Mission: Earth, Noah Parker, after being rescued from Maximus's citadel, where he was accidentally transported to, has discovered Betty's secret identity as a Galactic Guardian, and Betty and DeGill officially allow Noah to join the Galactic Guardians as a cadet, and is known officially as Cadet Noah. Galactic Guardian Headquarters was destroyed and Admiral DeGill decided to build their new headquarters on Earth, the idea of which was opposed only by Betty, unfortunately she could not win the argument and the base was located under her hometown of Moosejaw Heights. Life for Betty has become more difficult due to now being forced to help her alien pals to blend in at Moose Jaw Heights, explain the many aliens that come out of Headquarters unauthorized, and as well as keeping her friends and Galactic Guardian headquarters hidden from people like Mr. Parker, Noah's father, who has a huge belief in aliens and if he found even one trace of aliens, the truth of the Galactic Guardians would be revealed.
- 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
- Amy - rival, also mean babysitter
- Max - rival, also mean babysitter
- Cassie - friend, also Amy's little sister
- Art Phillips - friend, also Dr. Todd Phillips' son
- Dr. Todd Phillips - science teacher
- Mr. Corville - original art teacher
- Miss Dowerly - art teacher, english teacher and history teacher
- Admiral DeGill - commanding officer
- Noah Parker - friend and possible crush
- Beatrixo - maternal grandmother
- Jimmy - maternal grandfather
- Principal Peterson - principal
- Regeena Peterson - friend
- Paloma - friend
- Penelope Lang - rival, also spoiled brat
- Chaz Lang - current crush and boyfriend
- Dylan - original crush and boyfriend
- Maximus I.Q. - rival
- Minimus P.U. - rival
- The Betty Clones - clones/"cousins"
Atomic Betty Redux
Atomic Betty Redux is a recently announced new series currently in production. Atomic Cartoons made the announcement via their updated website in June 2010.
Details are unknown at this time, but it has been revealed that Betty will be "all grown up", which could mean she'll either be a teenager or an adult. She was first featured in the episode The Future Is Now!. It was the last episode before the series ended on January 29, 2008.  However, all references to this proposed sequel series were removed from Atomic Cartoons' official web site afterwards.
- In the Atomic Betty pilot, Betty's missions took place at night but in the television series, Betty's missions took place at both day and night.
- Also, Betty's voice sounds a little similar to Blossom from The Powerpuff Girls.
- Also, 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. She met unusual and unexplain things and she doesn't believe people on Earth would be Galactic Guardian.
- Many fans believe that Betty has an older brother, that he recruted Betty and is her master and that the reason he hasn't made an apperance is because he's in college.
- Many fans hope the show's revival will feature an episode that reveals who recruited Betty, when she was recruited and at what age she was recruited.