Memphis, an Elvis like emperor penguin (voiced by Hugh Jackman) and Norma Jean (Nicole Kidman) fall in love and have a baby egg. As is custom, the mother penguins leave for the winter to hunt for fish while the fathers remain to nurse and incubate the eggs. During the winter storm, Memphis gets excited while singing and drops the egg down a hill which rolls down it just a bit. Once winter is over, Mumble is the very last egg to hatch. After being hatched, his feet keeps dancing; which is not penguin-like since penguins are suppose to sing their "heart song" to find their true love.
After a night of celebration by all other penguins who graduate, Mumble ruins the celebration with his awful singing and leaves the group; only to wake up the next day on an isolated iceberg. After being chased by a giant seal, he meets 5 other penguins who befriends Mumble.
All the while, there is a fish shortage, and Noah, the most respected penguin who is looked at as the leader of the penguins, believes the Great 'Guin is the one who gives and takes away the fish and that all the penguins just need to continue worshipping and soon more fish will come. Mumble, while sliding around mountains, discovers a crane and believes Aliens (humans) are responsible for the fish shortage. When he suggests this as the reason why there is no fish, he is banished from Emperor Land. He vows to return once he discovers who has taken the fish. He sets out on a journey to appeal to the better nature of humans and try to ration with them to stop stealing the fish.