The film starts with Mack Mallard (Kumail Nanjiani) telling a bedtime story to his kids, Dax (Caspar Jennings) and Gwen (Tresi Gazal). He tries to keep them scared over leaving their pond for fear of running into large predators that might harm or kill them. Gwen ends up afraid, but Mack's wife/their mom Pam (Elizabeth Banks) admonishes Mack for trying to scare their kids. Mack defends himself by saying that having these fears will keep them safe.The next day, as the Mallards are enjoying their time by their pond, another flock of ducks arrive on their migration. Dax approaches a girl duck his age named Kim (Isabela Merced), and he appears smitten by her (which Gwen teases him for). Kim mentions that she and her family are flying to Jamaica for their migration and invites Dax and his family to join. Mack comes in and behaves rudely toward the other ducks, saying that he and his family are perfectly fine there. The other ducks leave, and Pam angrily tells Mack off for how he acted and how she feels the family is missing out on life because of how scared he is.Mack later finds the family's Uncle Dan (Danny DeVito), who strayed from his nest. He overheard the family's earlier argument and sides with Mack, saying that traveling is unnecessary. This makes Mack realize that if he continues to live this way, he will end up like Uncle Dan (alone), so he wakes the family up and decides to go ahead with taking the trip to Jamaica, to the family's delight. When Uncle Dan refuses to join (which Mack is thankful for), Gwen uses her cute face to try to convince him, which works (and Mack is upset again).The Mallards take off and leave the pond for the first time, but they find that the other birds are flying in the opposite direction. They end up in a storm and take shelter before being found by a heron named Erin (Carol Kane). Although she creeps them out, she offers the Mallards a place to stay for the night along with her husband Harry. After the herons go to sleep, the family tries to sneak out, but Erin catches them and tries to stop them. The Mallards think she is going to eat them until a large fish emerges and tries to swallow Dax and Gwen whole before Erin saves them. Mack and Pam are thankful and stay the rest of the night.The Mallards bid the herons farewell and continue their journey. Dax takes them up to the skies where they play in the clouds before finding themselves in New York City. Uncle Dan gets separated from them and winds up in Central Park. He finds a sandwich and tries to eat it but ends up confronted by a flock of pigeons. The rest of the Mallards arrive, and Mack calls the pigeons "trashy vermin", which offends them all. Their leader, a pigeon with one bad talon named Chump (Awkwafina), comes to confront Mack, but Pam steps in and negotiates for the pigeons and Uncle Dan to share the sandwich. The family tells Chump their situation, and she says she knows a bird who can get them to Jamaica.Chump guides the Mallards to a restaurant to meet a parrot named Delroy (Keegan-Michael Key), who was born and raised in Jamaica until a Chef took him from his home and kept him as a trophy pet. This is also when the family learns that ducks like them get cooked and served for dinner. When the Mallards offer to break him out, Delroy says the key to his cage is kept on the Chef's person at all times. Mack and Pam sneak into the kitchen. They end up causing a ruckus that enrages the Chef and causes him to chase after them. Mack and Pam end up on the dance floor just as the patrons start to gather for salsa night. They end up dancing their way out of the commotion before making it back to the room. Mack accidentally swallows the key before he can free Delroy, and the Chef catches up to them. In the chaos, Mack regurgitates the key, and Delroy frees himself before the other birds follow.The Mallards say goodbye to Chump and follow Delroy on his way back to Jamaica. Gwen then complains that she needs to poop, but she's too embarrassed to do it in the sky. This makes the family stop to land, and they end up finding what appears to be a duck sanctuary, along with a yoga instructor called GooGoo (David Mitchell). The Mallards then have fun like at a water park, but Dax then finds moments later that the Chef is arriving to collect the other ducks there, since it is actually a duck farm. Dax is spotted, and his wings get damaged by the Chef. He runs to warn everyone else, and all the ducks (and Delroy) manage to fly away.The ducks hide at night, but the Chef locates them using his helicopter. He catches all the birds except for Dax and Gwen with his net, and Dax's wings are in no shape to fly. The two watch as their parents get taken away, but Dax then gets an idea using Delroy's molted feathers.Onboard the helicopter, Pam laments their situation and says that Mack was right about staying at the pond, but he encourages her not to give up. Since Chef locked them in the same cage, they work together to walk out and try to free Uncle Dan, Delroy, and all the other ducks, but Chef catches them again. The other birds retaliate and pelt Chef with produce until he accidentally hits the bottom hatch, causing him and Mack and Pam to fall. Chef gets caught in the net, but Mack and Pam continue to fall until Dax and Gwen arrive, with Dax using Delroy's feathers to help him fly. They free their parents and hug while Uncle Dan and Delroy free themselves and all the other ducks.The flock makes their way to Jamaica, as they find the water glowing and end up on the island. Dax reunites with Kim, while Mack thanks Pam for helping him get the family out for once. The birds then have a dance party.When the spring comes, the Mallards find that a flock of penguins has shown up and needs help getting back to the South Pole. They then set off on yet another family trip.