On Tweedy's Egg Farm somewhere in the English countryside, the egg-laying hens live in fear of facing the repercussions dealt out by the farm's profit-hungry owner, Mrs. Tweedy (voice of MIRANDA RICHARDSON) for not delivering their quotas. That is, except for Ginger (voice of JULIA SAWALHA), a hen whose determined escape attempts end with her being captured by the somewhat dimwitted Mr. Tweedy (voice of TONY HAYGARTH) and repeatedly thrown into solitary.
Things appear to look up when Ginger spots Rocky "The Flying Rooster" (voice of MEL GIBSON) flying through the air before crashing into their gated and fenced compound. An American who refers to himself as the "Lone Free Ranger," Rocky immediately melts the hearts of most of the hens, save for Ginger and Fowler (voice of BENJAMIN WHITROW), the farm's resident RAF veteran rooster.
Even so, Ginger believes that Rocky can teach the hens to fly and thus escape in mass from the farm. This couldn't come at a more fortunate time as Mrs. Tweedy has recently decided to turn the farm into a chicken processing plant and has just purchased a chicken pie assembly line machine. Although Rocky's injured arm presumably is what's preventing him demonstrating his flying prowess, something else makes him reluctant. Since Ginger and the others successfully hid him from his former circus owners, however, he agrees to help teach the hens how to fly, even if he's not sure exactly how to go about doing that.
As Mac (voice of LYNN FERGUSON), the bespectacled brain of the group tries to figure out the physics involved in such flight and two traveling salesman/barterer rates, Nick (voice of TIMOTHY SPALL) and
Fetcher (voice of PHIL DANIELS) get their jollies out of watching their efforts, the hens, including Babs (voice of JANE HORROCKS) and Bunty (voice of IMELDA STAUNTON), put all of their faith in Rocky, although they soon learn that might not have been the wisest move.
Even so, with Mr. Tweedy repairing the monstrous chicken pie machine after an unsuccessful first run and Mrs. Tweedy raring to go in using the hens to increase her profits, Ginger and her friends race against time to get out of the farm before they end up in the pies.