Red is an angry bird and an outcast from the others on Bird Island ever since he was a hatchling due to his short-temper and his huge, jet-black eyebrows. When it causes a premature hatching of another bird's egg, he sentenced to anger management class, which is the highest penalty allowed on the island. Red's classmates Chuck, who is hyperactive and can move at hypervelocity, and Bomb, who can cause explosions with his anger and fear, try to befriend him, but he avoids them.
One day, a boat docks at the island's shore, damaging Red's house. The birds greet two green-colored pigs, the captain Leonard and his assistant Ross, who claim to become peaceful explorers bringing offerings of friendship. The pigs introduce the birds to various innovations, including a giant slingshot, but Red becomes suspicious of the pigs' motives and sneaks into Leonard's boat where he finds more pigs hidden below deck, contradicting Leonard’s claim that it was just him and Ross. When he returns and shows everyone the other pigs, the birds refuse to believe his claim that the pigs are up to no good, and Leonard claims that he only lied to see if Bird Island was safe for his cousins.
Determined for help, Red recruits Chuck and Bomb to find Mighty Eagle, the protector of Bird Island and the only bird on the island who can fly, who has not been seen for many years. They find Mighty Eagle on top of Eagle Mountain, only to find that he has not flown for years, and that he is overweight, self-absorbed, and leading the life of a slacker. Red realizes that his suspicions were right when he discovers the pigs planting dynamite around the island, and realizes the pigs are planning to steal the birds' eggs while distracting the other birds, who seem unaware of the trio's absence, with a party. Red pleads for Mighty Eagle to help him, Chuck, and Bomb, but he refuses. Red admonishes Mighty Eagle before he, Chuck, and Bomb leave. The trio race back to try to sound a warning to the other birds and stop the pigs, but the pigs escape with the eggs and activate the dynamite, destroying the village. The other birds apologize to Red for not listening to him. Red forgives everyone and under his leadership, they organize an army and build a boat from the rubble to follow the pigs to Piggy Island.
The birds discover the pigs living in a walled city ruled by Leonard, whose full name is King Leonard Mudbeard. Deducing that the eggs are in the castle at the center of the city, the birds use the slingshot to attack by launching themselves over the walls and into the city's buildings, destroying them. Red, Chuck, and Bomb infiltrate the castle and discover that the eggs are inside a net; the pigs plan to lower the eggs into a giant pot, cook them, and eat them. Mighty Eagle arrives to retrieve Red's group and the eggs, having had a change of heart. One egg falls out of the net and Red battles Leonard for it, but learns to control his anger and distracts him long enough to retrieve the egg. Leonard accidentally ignites the pigs' reserve of dynamite, and a pot collapses and lands on top of Red, shielding him and the egg he was holding from the blast as the dynamite explodes, destroying the city.
All the families, except for one, reunite with their eggs. Red emerges holding the egg, which has hatched, and returns the babies to their parents. Mighty Eagle approaches Red, Chuck, and Bomb, claiming he merely appeared lazy so they could lose faith in him and find faith in themselves, and takes credit for saving the eggs. Red discovers the other birds have rebuilt his house in the center of the village. Moved, Red allows Chuck and Bomb to move in with him. The pigs survive their home's destruction, with Leonard plotting a new plan.
In a mid-credits scene, the three blue birds use the slingshot to launch themselves out towards the ocean.
Jason Sudeikis as Red
Aidan McGraw as young Red
Josh Gad as Chuck
Danny McBride as Bomb
Maya Rudolph as Matilda, Poppy
Kate McKinnon as Stella, Eva
Sean Penn as Terence
Tony Hale as Ross,[d] Mime, Cyrus
Keegan-Michael Key as Judge Peckinpah
Bill Hader as King Leonard Mudbeard
Peter Dinklage as Mighty Eagle
Blake Shelton as Earl
Anthony Padilla as Hal
Ian Hecox as Bubbles
Charli XCX as Willow
Tituss Burgess as Photog
Billy Eichner as Chef Pig, Phillip
Hannibal Buress as Edward
Ike Barinholtz as Tiny
Max Charles as Bobby
Jillian Bell as Helene, Yoga Instructor
Cristela Alonzo as Shirley
Danielle Brooks as Monica, Olive
Kevin Bigley as Greg
Adam Brown as Hug Trader
Romeo Santos as Early Bird
Geoffrey Arend as Day Care Teacher Bird
Ava Acres as Timothy
Alex Borstein as Sophie Bird, Peggy Bird
Malena Brewer as Arianna Bird
Vincent Oswald as Dylan Hatchling
Samantha Cohen as Samantha Hatchling
Josh Robert Thompson as Brad Bird, Dane the Saxophone Bird
Matt McCarthy as Rodney Pig and John Hamm (credited as Acrobat Pig)
Matt Taylor as Hamilton Pig and Oinky (credited as Acrobat Pig)
Mckenna Grace as Ella Bird
Ali Wong as Betty Bird
Fred Tatasciore as Monty Pig
Bella Laudiero as Maya Bird
John Cohen as Johnny Bird
Clay Kaytis as Clayton the Waiter Bird
Fergal Reilly as Foreman Pig
Catherine Winder as Billy the Sign
Carlos Alazraqui as Earl's 2nd Brother
Eileen Marra, Indra Raval, Joaquin Raval and Sofie Wolfe as Hatchling Singers