A pink-haired girl named Stephanie moves to LazyTown with her uncle (the mayor of LazyTown), where she tries to teach its extremely lazy residents that physical activity is beneficial.
When Stephanie arrives in LazyTown, to spend the summer with her Uncle Milford, she finds that she has trouble making friends because all the local kids spend all their time indoors playing video games. So, her uncle enlists the help of Sportacus, an athletic hero who encourages the kids to have fun by remaining active. Unfortunately, this doesn't sit well with Robbie Rotten, a lazy cheat, who takes pride in having LazyTown be the laziest town around, so he plots to get rid of Sportacus.
Sportacus tries on a new pair of shoes, unaware that they are actually radio-controlled boots that Robbie will use to ruin Sportacus' athletic skills during Spectacular Sports Day.
The kids must face Robbie Rotten in a sports competition without the help of Sportacus after the villain causes the athletic hero to suffer a Sugar Meltdown brought on by a candy apple.
Sportacus loses his Crystal and offers a reward of one free wish to whoever finds it and returns it. Robbie sees this as the opportunity to get the free wish and use it to wish Sportacus out of LazyTown.
Robbie discovers that plenty of sleep gives people much needed energy, so he plots to rob Sportacus of his precious sleep so that he'll become weak and lose an upcoming baseball game.
Bessie's birthday cake turns up missing, and Robbie tricks everyone into believing that Sportacus stole it. The accusations land Sportacus in jail, so the kids get together to prove that he's innocent.
Ziggy tries to be a hero just like Sportacus, but his antics start getting him in trouble when he messes up the construction of the kids' new clubhouse.
The kids are compelled to do whatever Robbie says and not question him when he disguises himself as Sportacus and gets them to act lazy.
Ziggy tosses out a toothbrush, a birthday gift from Sportacus, in favor of a taffy machine from Robbie Rotten. Soon, Ziggy is unable to stop the gadget when it begins to get out of control and covers LazyTown in taffy.
The kids join the Lazy Scouts, led by Scoutmaster Robbie, who promises to teach them the easy and lazy way to go camping. This doesn't sit well with Stephanie, especially when she discovers that the kids are ill-prepared for an oncoming storm.
Robbie causes panic in LazyTown when he disguises himself as Dr. Rottenstein and makes everyone believe that vegetables are at the root of a new disease.
Robbie tricks the kids into going on a treasure hunt for the LazyTown Stone and then tries to steal it from them until Sportacus arrives to stop Robbie, much like a mysterious hero once stopped the famed Rottenbeard.
Stephanie and Stingy campout with a scared Ziggy who thinks he's seeing a dinosaur roaming about.
The kids enter a treehouse building contest, but find it difficult working with Stingy because he doesn't know how to work as a team.
The kids attempt to raise the Energy Meter in order to avoid being named the Laziest Town.
A missing page from Stephanie's diary causes trouble amongst the kids.
Pixel invents a machine that makes things vanish, and Robbie tries to get his hands on it so that he can get rid of Sportacus.
Everyone in town is busy trying to set new world's records, with Robbie trying to make LazyTown the World's Laziest Town.
Robbie fools Stingy into thinking that he's the Prince of LazyTown which soon gets him into trouble.
Pixel designs a LazyTown website about the town's residents, but neglects to include Robbie.
The kids celebrate a day devoted to playing games.
Pixel creates a remote that controls everything.
Robbie uses a device to erase Sportacus' memory.
Robbie uses a soccer-playing robot to play against Sportacus in a game.
The kids learn to misbehave from Robbie when he disguises himself as a manners expert named Miss Roberta.
Sportacus takes a holiday and leaves LazyTown in the hands of his good friend Stephanie. As SportaStephanie, she faces her first big challenge when Robbie unleashes a hero-hating machine called Robo-Dog.
Sportacus and the kids help Mayor Meanswell become a secret agent so that he can find out how Robbie Rotten won a race to become mayor of LazyTown.
Stephanie and Ziggy go around LazyTown asking everyone what are their favorite LazyTown songs.
It's the Christmas season in LazyTown, and everyone's getting ready for a holiday party. Robbie Rotten soon spots this, but declares that he wouldn't go even if he was invited. He hatches a plan to dress up as Santa Claus and spoil everyone's holiday fun. Meanwhile, Stingy is having trouble understanding the spirit of Christmas. He just loves the gift-getting, but can't quite seem to get into the gift-giving.
Mayor Meanswell is once again getting ready to present the Person of the Year trophy to Sportacus, but can't seem to keep it a secret that Sportacus is the winner. When he hears that Sportacus is winning again, Robbie decides to put a stop to it. Considering the past failures of his evil plans, he decides to hit Sportacus with several of his past failures, hoping that they'll combine into a success.
The kids decide to grow fruits and vegetables for a Sports Candy Festival for Sportacus. However, Robbie wants them to stop eating healthy foods and ruin the festival, so he disguises himself as life-size fruits and vegetables, hoping to scare the kids and stop the festivities.
A dance competition is underway in LazyTown. Robbie believes that if Stephanie wins, LazyTown will become too active, so he creates a clockwork dancing girl to compete against her.
Robbie poses as an alien named Zobby and befriends Ziggy, so the other kids decide to blast Zobby home to his own planet in a rocket.
A day in the life of Sportacus as he goes about his daily routine as a superhero, performing incredible stunts and saving all the residents of LazyTown including Robbie.
