Every emperor penguin sings a unique song called a “heartsong” to attract a mate. 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, 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 yellow band, which he says is from an alien abduction. Mumble narrowly escapes the hungry birds by falling into a crevice.
Now a young adult, Mumble is frequently ridiculed by the elders. After escaping from a leopard seal attack, Mumble befriends a group of Adelie penguins called “the Amigos”, who embrace Mumble’s dance moves and assimilate him into their group. After seeing a hidden human excavator in an avalanche, they opt to ask Lovelace, a rockhopper penguin, about its origin. Lovelace has the plastic rings of a six pack entangled around his neck, which he claims to have been bestowed upon him by mystic beings.
For the emperor penguins, it is mating season and Gloria is the center of attention. Ramón, one of the Amigos, attempts to help Mumble win her affection by singing a Spanish version of “My Way”, with Mumble lip syncing, but the plan fails. In desperation, Mumble begins tap dancing in synch with her song. She falls for him and the youthful penguins join in for singing and dancing to “Boogie Wonderland”. The elders are appalled by Mumble’s conduct, which they see as the reason for their lean fishing season. Memphis begs Mumble to stop dancing, for his own sake, but when Mumble refuses, he is exiled.