Every emperor penguin sings a unique song called a "heartsong" to attract a Mating. If the male penguin's heartsong matches the female's song, the two penguins mate. Norma Jean, a female penguin, falls for Memphis, a male penguin and they become mates. They lay an egg, which is left in Memphis' care, while Norma Jean leaves with the other females to fish. While the males struggle through the harsh winter, Memphis briefly drops the egg. As a result, their son, Mumble, is unable to sing, but he can tap dance instead. Nevertheless, he is enamored with Gloria, a female penguin who is regarded as the most talented of her age. One day, Mumble encounters a group of hostile skua, with a leader who is tagged with a bird ringing, which he says is from an alien abduction. Mumble narrowly escapes the hungry birds by falling into a crevice.
Mumble the penguin has a problem: his son Erik, who is reluctant to dance, encounters The Mighty Sven, a penguin who can fly! Things get worse for Mumble when the world is shaken by powerful forces, causing him to brings together the penguin nations and their allies to set things right.