Once cherished heroes, superheroes around the world are forced into retirement by a wave of litigations against collateral damages they cause. Among them is Bob Parr, who formerly saved lives and fought evil under the name Mr. Incredible. Yearning for his glory days, Bob lives a sigh-inducing suburban life as an insurance adjuster with his wife Helen, the erstwhile Elastigirl, and their three children, each struggling with their own unique powers. Their attempts to live as a normal family, however, are constantly disrupted by Bob's nostalgia for heroism, leading to clandestine crime-fighting escapades that strain his personal life.

Bob's passion for action is reignited when he receives a mysterious communication inviting him to a remote island for a top-secret assignment. This reawakening propels him into a trap set by a resentful new villain, angered by past superheroic snubs. While Bob contends with this emerging threat, Helen suspects something is amiss and, along with her children, sets out to uncover the truth. As the family uncovers deeper layers of deception, they begin to realize that they must rely on each other and embrace their superpowers to confront the menace facing them.