Two decades after the events at Jurassic Park, a new theme park, Jurassic World, now operates on Isla Nublar, off the Pacific coast of Central America. This new park is run by the Masrani Global Corporation, which also owns InGen, the genetics company that creates the dinosaurs. Brothers Zach and Gray Mitchell are sent to Jurassic World by their divorcing parents to visit their aunt, Claire, the park's operations manager. Claire, a busy workaholic, assigns her assistant to be the boys' guide.
Navy veteran Owen Grady trains the park's four Velociraptors that have imprinted on him as their pack alpha. Vic Hoskins, of InGen security, believes that raptors are trainable for military use, despite Owen's disputing this. Meanwhile, Park owner Simon Masrani has Owen evaluate the park's new hybrid dinosaur, Indominus rex, before the attraction opens. Owen warns Claire that the Indominus, raised in isolation, is particularly dangerous because it is not socialized to other animals.
When the Indominus has seemingly escaped its paddock, Owen and two staff enter the enclosure. The Indominus, able to camouflage itself and mask its heat signature, ambushes them before escaping into the island's interior. Owen wants it killed, but Masrani sends the Asset Containment Unit to capture the dinosaur alive. When most of the ACU team are killed, Claire orders the island's northern sector evacuated.
Zach and Gray, exploring in a gyrosphere ride, ignore the evacuation order and wander into a restricted area where the Indominus attacks and destroys the sphere. The boys escape unharmed and come upon the ruins of the original Jurassic Park Visitor Center. After repairing an old Jeep, they drive back to the park resort. Claire and Owen, who are searching for the boys, barely escape the Indominus themselves. Masrani and two troopers hunt Indominus by helicopter. Indominus smashes into the park's aviary to escape gunfire, releasing pterosaurs that collide with the helicopter. It crashes, killing everyone aboard. Gray and Zach find Owen and Claire at the resort as armed troopers shoot the swarming pterosaurs.
Assuming command, Hoskins orders the raptors be used to track the Indominus; Owen is forced to accept Hoskins' plan. The raptors follow Indominus ' scent but after encountering it, the animals begin communicating with one another; Owen realizes that Indominus was created with raptor DNA; it becomes the pack's new alpha. Hoskins, meanwhile, has Dr. Wu helicoptered off-site with dinosaur embryos, protecting his research. Owen, Claire, and the boys find Hoskins at the lab packing up more embryos, but a raptor breaks in and kills him.
Owen reestablishes his alpha bond with the three surviving raptors before the Indominus reappears. Two raptors are killed attacking it. Claire orders the park's veteran T. rex to be released from its paddock and lures it into a vicious battle with the Indominus. The T. rex is overpowered until the lone surviving raptor attacks. The raptor and T. rex force the overwhelmed Indominus towards the lagoon, where it is dragged underwater by the park's resident Mosasaurus.
Survivors are evacuated to the mainland, and the island is abandoned to the dinosaurs. Zach and Gray are reunited with their parents, while Owen and Claire decide to stay together.