Madagascar

Alex the lion, Marty the starry-eyed zebra, Melman the hypochondriac giraffe and Gloria the "hip", slightly chubby hippo have a pampered life at the Central Park Zoo in New York City where they show off to the crowds and generally enjoy themselves. But Marty, celebrating his tenth birthday, longs to see the rest of the world and dreams of life in the wild. When he learns that the zoo's penguins are planning to escape he decides to follow suit, and return by morning. He has a vague notion that the wild can be found in Connecticut, so one night he sneaks out of the zoo and sets off on foot for Grand Central Terminal, where he hopes to take the Metro-North Railroad to Connecticut.

When the others find him gone, they head for Grand Central Station via the Subway to try and get him back. Arriving at Grand Central, they scare away most of the passengers (except for one determined old lady who leaves Alex on his toes) and catch Marty. They then manage to wreck the information desk before being shot with tranquilizer darts, along with the penguins and Mason and Phil, two chimpanzees who also escaped. Anti-zoo campaigners use the incident as evidence that animals should not be locked up. Because of this, all the animals soon find themselves in wooden crates aboard a cargo ship to Kenya.

The penguins succeed in taking over the ship and changing its course, following their initial plan of making their way to Antarctica. During the penguins' takeover, the crates containing Alex, Marty, Melman and Gloria fall overboard and they become separated on the ocean. Alex is washed ashore on a tropical beach. All night he is alone, but in the morning finds Melman stuck in his crate. Gloria and Marty soon wash ashore on the beach too. At first Melman assumes they are in San Diego, and Alex is upset that he will be outshone by Shamu, but when they discover a large tribe of lemurs led by King Julien XIII (voiced by Sacha Baron Cohen), they realize they are not in the United States anymore. They are actually in the wild, on the island of Madagascar.

Alex is furious with Marty, blaming him for the group's situation. He divides the island between them and forces Gloria and Melman to help him build a beacon-holding Statue of Liberty lookalike. His plan is to ignite the beacon, making them easy to notice for the boat, which Alex believes is coming to rescue them. However, Melman accidentally sets the whole statue on fire and destroys it. Gloria and Melman then join Marty, and Alex soon decides that he has been a jerk to his friend and joins the others to live on Madagascar.

Meanwhile, the penguins arrive in snowbound, windswept Antarctica and decide that "Well, this sucks..."

Julien hopes that the lemurs' new friends, whom he calls the "New York Giants", will scare away the foosa, enemies of the lemurs who have been preying on them. Despite the protests of his advisor Maurice (who thinks that Alex, as a carnivore, might be dangerous), Julien convinces the lemurs to welcome Marty and the others to their own little corner of paradise.

Unfortunately Alex, who has only ever eaten pre-cut steaks until now, is beginning to regain his natural predatory instincts. After losing control and attacking Marty, he is considered too dangerous to be a friend to his zoomates, or to any of the lemurs. Julien admits that Maurice has some sense in fearing Alex, and banishes the lion to the side of the island dominated by the foosa, just before everyone ends up running for their lives. Alex came to his senses for a time after a knock on the head by a coconut, and made the decision to leave his friends behind rather than do something he'd later regret. Marty, now completely aware of the predatory factor of the wild, is devastated at the realization that this is happening to him.

The penguins soon arrive in the ship. Realizing this may be a way back into New York, Marty goes to find Alex (against Gloria's advice). He ends up deep in foosa territory where he unsuccessfully tries to get Alex to come with him. The foosa eventually attack him, and soon he, Melman, Gloria and the penguins end up fighting for their lives, hopelessly outnumbered by the hungry creatures. Then Alex appears. At first he seems to have completely returned to his hunting instincts and claims Marty as his own prey. But this turns out to be a ruse: Alex has managed to overcome his predatory instincts. Using the foosa's natural fear of him, Alex drives the predators away from lemur territory forever. Needless to say, Julien made it clear that his original plan was a huge success.

Following a celebration dinner, at which Alex's hunger is finally sated by the discovery that he likes fish even better than steak, the friends return to the ship, leaving the penguins behind, and plan a round-the-world cruise, unaware that the ship is out of fuel, thus making this their permanent home.