Playing around while aboard a cruise ship, The Chipmunks and The Chipettes accidentally go overboard and end up marooned in a tropical paradise. They discover their new turf is not as deserted as it seems.
During a cruise for a family vacation, The Chipmunks and The Chipettes turn the ship into their personal playground, causing trouble. Dave notices that his old boss Ian Hawke is working as a pelican on the cruise and watching to see if the Chipmunks misbehave. Alvin and Simon were grabbed by Dave (Theodore is watching Jungle Monster 4) when they are caught in the casino. The captain allows them one more activity: Shuffleboard. Alvin decides to go para-sailing on a kite and he is blown away with the other chipmunks who are holding on. Dave tries to take a hang glider to go after them but Ian attempts to stop him and they both end up in the ocean.
Meanwhile, the six chipmunks find an island and sleep for the night. Dave enlists Ian's help find the same island and begin looking for the six chipmunks.
The next morning, The Chipmunks go and find food and while doing so, an island castaway named Zoe shows up and sees The Chipmunks and The Chipettes for the first time. They then go to Zoe's tree house on a zip line. As Eleanor tries to get out of the basket, she falls and sprains her ankle. Soon after Simon gets bitten by a spider that carries a neurotoxin. Zoe said it isn't a big deal and that she is normal, despite being bitten twice a day the spiders.
When Alvin prepares to sleep, Simon has trouble sleeping. The next morning, Theodore observes Simon's personality has changed, becoming a French, adventurous chipmunk named Simone and follows him. The two of them go bungee jumping.
Once Simone meets The Chipettes, he is overtaken by Jeanette and asks her to dance at Alvin's dismay. Later, Zoe takes Simone, Jeanette, Eleanor, and Theodore to a waterfall and Simone finds a cave while Alvin and Brittany are on the beach finding wood to make a shelter. He returns with a gold bracelet which he gives to Jeanette.
The next day, Brittany and Alvin see an active volcano and they all decide to leave the island. Theodore and Simone finally find Dave and Ian. When they all get together, preparation of a raft to get them off the island goes underway and everyone is assigned a job.
When the raft is finished, Jeanette and Simone are still in the forest looking for food. Suddenly, Simone gets knocked out with Zoe's golf ball and Zoe kidnaps Jeanette (with the help of her basketball). Simon goes unconscious and reverts to his normal self when he wakes.
When Simon is found, he cannot remember anything since the bite. Brittany, figuring Zoe is responsible, asks him where he found the gold bracelet that he gave to Jeanette, but he doesn't remember. Brittany then asks Eleanor how to get there. When they approached the tree log to cross, Dave and Alvin decide they'll go and find Jeanette, while Ian and other chipmunks go back to the coast.
Zoe meanwhile forces Jeanette to get the treasure by tying her to a rope. As Alvin and Dave come to her rescue, the island begins to rumble again and Zoe lets go of the rope. Jeanette runs with Dave and Alvin back to the raft but is pulled back at the log bridge. Simon swings in to help Jeanette before Alvin can cut the rope with his Swiss Army Knife. Dave is left hanging from the log when it almost gives way.
After Alvin and Ian convince Zoe to help save Dave, they run towards the raft and escape the eruption. While on the raft, Zoe apologizes to Jeanette for kidnapping her and forcing her to get the treasure. As a gift, Jeanette gives Zoe the gold bracelet that Simone had given to her. Alvin reconciles with Dave and they are rescued.
The Chipmunks and The Chipettes perform at the International Music Awards. Ian regains his career and job back by selling Zoe's story to Hollywood.
In the film's epilogue, The Chipmunks, The Chipettes, and Dave are on a plane heading back home. Alvin is speaking on the pilot's microphone that the plane's destination is set for Timbuktu, when flight attendant tell the plane will start to fly, Alvin accidentally pushes the food cart, which hits Dave. He then screams, "ALVIN!".
The film closed in the United States on June 7, 2012. It was a huge box office success, with a final domestic earning of $133,110,742 and a worldwide earning of $209,584,693 for a grand total of $342,695,435, making it the third highest grossing Alvin and the Chipmunks film.
- Jason Lee as David "Dave" Seville
- David Cross as Ian Hawke
- Jenny Slate as Zoe
- Alyssa Milano as Daphne Snow
- Andy Buckley as Captain Correlli
- Justin Long as Alvin Seville
- Ross Bagdasarian, Jr. as Alvin Seville (singing)
- Matthew Gray Gubler as Simon Seville
- Jesse McCartney as Theodore Seville
- Janice Karman as Theodore Seville (singing)
- Christina Applegate as Brittany Miller
- Janice Karman as Brittany Miller (singing)
- Anna Faris as Jeanette Miller
- Janice Karman as Jeanette Miller (singing)
- Amy Poehler as Eleanor Miller
- Janice Karman as Eleanor Miller (singing)
- Before the film's release, it was once rumored that Theodore was going to have a nightmare when him, his brothers, and The Chipettes are stuck on an island.
- So far, every Alvin and the Chipmunks live-action film has premiered in December.
- Also, every movie ends with Dave screaming his trademark "ALVIN!".
- This is the second time The Chipettes star with the The Chipmunks in the CGI films.
- Ian returns as an employee on the cruise ship.
- It was rumored that a new character named "Munk-Y" would be in this film. The character is in fact Simon who goes by the name "Simone" after being bitten by a spider whose side effects make Jeanette fall in love with him.
- It was also rumored that in the film that The Chipettes were to be The Chipmunks' girlfriends. However, the novel does have some scenes where it is hinted that one of them (Simon and Jeanette) have a romantic feeling.
- Eleanor twists her ankle after falling from a zip line, which results in her using crutches for most of the film.
- The film is likely based on the Alvin and the Chipmunks episode Island Fever.
- Claire, Miss Miller, Toby, and Aunt Jackie do not appear in the film.
- This is the second film that The Chipmunks get mistaken for squirrels, although the first for The Chipettes.
- Unlike the first two films, Ian reforms and helps Dave rescue the chipmunks. Despite this, he does threaten to eat Theodore's necklace and Dave if they didn't find the chipmunks soon. In the end, he finally gets his career back.
- Instead of Matthew Gray Gubler voicing Simone, Alan Tudyk voices him.
- Jeanette is the first of the six CGI Chipmunks to sing a solo song "S.O.S."
- Simone is the third character to speak French in the films.
- The ship they were traveling on is the Carnival Dream.
- First movie where the DVD scene selections are unnamed.
- When Simone and Jeanette dance in the rain, Simon has became Simone. However, when he sings, "Say Hey," his voice is normal.
- Brittany is seen wearing her golden dress from the previous movie (in the magazine). Despite this, in the stage, she wore her pink dress.
Theodore: "Um..." (sees sad Eleanor) "Eleanor, would you care to dance?"
Eleanor: (brightens up) "I'd love to."
Theodore: "With... me?"
Eleanor: (giggles and throws her crutches to the side) "YES, Theodore!" (grabs Theodore's hand and pulls him out onto the "dance floor") ______________________________________________________________________________________
Simon: "What gold bracelet?"
Brittany: "The one you gave to Jeanette."
Simon: "What? When did I give Jeanette a bracelet?"
Brittany: "On your date..."
Simon: (gasps) "JEANETTE AND I ARE DATING?!"
Brittany: "Okay, he's useless."
Zoe: "Okay, you..." (ties Jeanette up) "You're not coming back up until you have every gem."
Jeanette: "B-b-b-but... THE VOLCANO IS ABOUT TO EXPLODE!!!!"
Zoe: "Guess you better hurry then, huh?" (drops Jeanette in the hole)
Jeanette: (sighs and starts singing) "S.O.S.. please, someone help me... it's not healthy..." ______________________________________________________________________________________
Jeanette: "Simone... what are you doing?"
Simone: "Something I wanted to do the very first moment I laid my eyes on you." (starts dancing with Jeanette) ______________________________________________________________________________________
Eleanor: (points right) "Go left!" (points left) "No... right!" (points right) "No, left!"
Ian: "I thought you said you knew where you're going!"
Eleanor: "I do! I just forget my left from my right..." (looks at hands) "Um... THAT WAY!" (points left) ______________________________________________________________________________________
Ian: (to Zoe) "All those pizzas I delivered to his house, wasted."
Dave: "Ian, that was you?"
Ian: "Not now, Dave."
Brittany: "I have no idea! The place where I get my nails done, always has the Science Channel on. Maybe I accidentally paid attention." ______________________________________________________________________________________
Jeanette: "I hope you don't mind... Simone gave it to me."
Simon: "Oh, I-I don't mind. Y-- You know, Jeanette, even the most perfect gem cannot compare to your beauty." ______________________________________________________________________________________
Zoe: (The Chipmunks and Chipettes are singing "Bad Romance") "Okay, stop! I don't know who you are."
Brittany: "Um... how long have you been here?"
Zoe: "Well, I got here on a Monday, so..." (counts on her fingers) "Yeah, eight or nine um... years."
Simon: "Nine years?! Wait, you've been here nine years?"
Zoe: "It could've been eight."
Brittany: "What if we're here nine years? What if we're here forever?!" (grabs Alvin's shirt and shakes him) ______________________________________________________________________________________
Brittany: "This is so not fair! Not to us, not to Dave and certainly not to the captain! Who I'm sure was looking forward to dining with me."
Simon: "What if I go speak to Dave? See if I can smooth things over."