In the movie Timmy is stuck with guarding the Abra-Cadabrium while the gang is in Hawaii, but Foop and Denzel Crocker hatch a plot to steal it from him. This is the first live-action movie to include Foop in CGI and live-action.
Get ready for the oddest summer yet! Timmy Turner and his fairies are going on a summer vacation to Hawaii. But, unfortunately for Timmy, something tells us this won’t be a very relaxing holiday. With all the magic in Fairy World at stake and villains like Vicky, Foop and Crocker on his tail, there’s no way he’ll be able to enjoy himself… But that doesn’t mean you can’t! Sit back and watch Timmy’s cray cray vacay adventure in A Fairly Odd Summer!
The movie starts as Timmy is seen in a tropical setting, running away from masked primitives. He falls into the inside of a volcano where Cosmo, Wanda and Poof are trapped, hanging by a rope up the lava. Crocker shows up in Hawaiian wear to reveal he is behind it, and threatens to release the fairies into the lava, when Tootie shows up in Tomb Raider-like costume and rescue them. The volcano starts falling apart as Timmy and the gang run away. They take a jet ski and leave, and as Timmy and Tootie kiss, it's revealed it's all part of one of the man-child's dream. Timmy Turner wakes up and is seen working on a summer job at a yuck disposer in Fairy World - it's unknown if the Wishful Thinking business is still running. However, Timmy is bored and hates the job, the only reason he took it was to impress Tootie, who was also in a summer job back in Dimmsdale, on a research lab dedicated to help helpless creatures.
Meanwhile, Marty and Mitzie, two rich kids, are in a limo with their parents, who are planning a family trip to Hawaii. As always happens for them, "a thing" makes it unable for Mr. and Mrs. Mulligan to go, but they decide to let their kids go anyway, and call Vicky to take care of them during the trip.
When Jorgen wants to go to Hawaii for a contest, he leaves Timmy in charge of taking care of the Abracadabrium, a magical stone revealed to be the source of The Big Wand, and consequently the power of every fairy. Foop hears about it and decides to steal it, but when he confronts the Anti-Fairy Council, they tell him Anti-Fairies can't touch the Abracadabrium, but order him to complete this task anyway.
Meanwhile, Tootie, and Timmy's parents are also leaving for Hawaii, as she needs to take a cure for dolphins to Hawaiian researchers, and Timmy's dad has to organize a luau for Pencil Nexus. Accidentally, Timmy ends up keeping Tootie's medicine and Dad's check, and decides he must also go to Hawaii to give them back their belongings. He takes the Abracadabrium with him, and puts The Big Wand in back-up power.
Denzel Crocker is also going to Hawaii, as his mother registered him in a trip with a group of help to insane people. When in the airport, he meets Foop, who fell there by accident. They team up to steal the Abracadabrium.
Timmy arrives in Hawaii and helps his parents and Tootie, with whom he goes out to have a good time. After several attempts, including have Foop turning into a human, him and Crocker finally succeed in stealing the stone, and The Big Wand's back-up powers starts going down, making fairies everywhere start getting weak and losing their powers. Tootie, alongside Marty and Mitzie, follow Foop and Crocker to a volcano where they plan to destroy the stone throwing it into the lava. When Crocker gives up doing it, due to the element's kindness affecting him, Foop traps him - with the Abracadabrium in hands -, Tootie, Marty, Mitzi and eventually Cosmo, Wanda and Poof in a rock in the middle of the lava, stating that the rock would melt, destroying them, and the magical stone.
However, Timmy shows up and finds a way to knock Foop down and take their friends to a safe spot. Foop tries to take the Abracadabrium out of Timmy's hands and as they start pushing it, they both end up falling into the lava and thought to be dead. Sad, Timmy's fairies and friends turn their back to leave when the lava starts glowing. Cosmo, Wanda and Poof realize their power has returned, and a glowing ball starts lifting until it turns into something: It's Timmy, floating, with his ten year old look, crown and wings. Wanda explains that he must have absorbed the magic from the Abracadabrium and turned into a fairy.
At that moment, Jorgen shows up and tells Timmy that now he’s a fairy himself, he doesn't need Fairy Godparents anymore, so Cosmo and Wanda would be reassigned to new children who needed them, Marty and Mitzie, but Timmy would keep seeing them from time to time, and would keep his job in Fairy World. Even being now a fairy, Timmy keeps hanging with Tootie, however they relationship status isn’t clear, as it's unknown if he’s able to magically change into his human self again.
Foop manages to survive as well, but before he could do anything, Poof delivers one big home run, causing Foop to hurdle himself out of the volcano into the night sky. And what happens to him in the final scene was the unspeakable horror the Anti-Fairies spoke of: Being flushed down a toilet.