Mr. Incredible is your standard superhero, he has super strength, he saves people, fights bad guys, and gets the girl. However, a young boy named Buddy Pine tries to be Mr. Incredible's side-kick with disastrous consequences. The public soon turn against super heroes so Mr. Incredible and his new wife, Elastigirl, move to the suburbs to live a normal life and have three children. His two oldest children, Violet and Dash have trouble fitting in at school, the former being incredibly shy (with the ability to turn invisible) and the latter being a troublemaker (with super-speed). However, Mr. Incredible is unhappy living a normal life and still goes after criminals with his friend and fellow super, Frozone.
Mr. Incredible receives a message from Mirage and heads to a mysterious island where he can fight evil robots (after a quick stop to visit Edna Mode for an updated costume). Feeling more fulfilled, Mr. Incredible is a better father and husband until he is captured by Buddy Pine, now the supervillian Syndrome. Mrs. Incredible becomes suspicious of her husband's disappearances and relationship with Mirage and goes to Edna to learn about Mr. Incredible's double life and the whole family receives new costumes. She goes to the island to retrieve him, but Violet and Dash stowaway on her airplane. The plane is shot down, but the family reach the island.
Mrs. Incredible goes to save Mr. Incredible, but the children are attacked by Syndrome's drones and the family is reunited as Mr. and Mrs. Incredible try to save the children, but the whole family is captured. Violet frees the family and they head to the city where Syndrome is sending attack robots. There they meet with Frozone to defeat the robots.
After the robots are defeated, Syndrome escapes, but heads straight to the family home to kidnap Jack-Jack, the baby of the family. As Syndrome is flying away, the baby's super powers first manifest allowing him to change form. Syndrome is unable to hold the baby (who is rescued by his mother) and is pulled into a plane propeller by his cape.
The family returns to their everyday life, but the children are both happier now that they have saved the day and more confident in their powers. The family is more than ready to snap back into action as heroes when threatened by The Underminer.