In a vibrant world inhabited by anthropomorphic animals, a struggling theater owner named Buster Moon, an optimistic koala, is on the brink of bankruptcy. In a last-ditch effort to save his beloved but failing theater, Buster conceives a plan to host a grand singing competition, inspired by his passion for show business and desire to rekindle his establishment's former glory. He scrapes together a modest prize amount through some creative financial maneuvers, hoping it will attract a crowd of talented performers. Through a series of mishaps, the flyers for the competition mistakenly advertise a prize vastly larger than what Buster can afford.

The city buzzes with excitement as animals from all walks of life seize the opportunity to change their destinies and pursue their dreams. Among the eclectic group of eager contestants are a swindling mouse with a smooth jazz voice, an overworked mother pig juggling her 25 piglets and a passion for singing, a teenage gorilla aiming to break free from his family's life of crime, an introverted elephant with an enormous case of stage fright, and a punk-rock porcupine trying to assert her artistic independence. As they embark on this musical journey, each contestant faces their unique set of challenges and personal struggles, hoping that the competition could be their chance at a life-altering breakthrough.