The nine-year-old grandson of John Hammond. Hammond had his grandchildren come to the island to visit Jurassic Park before it opened to the public. Tim has an incredible knowledge of dinosaurs from reading books by Robert Bakker and Alan Grant. Tim likes to taunt his older sister, Lex Murphy, and he talks so much about dinosaurs that Dr. Grant gets annoyed with him. However, Tim and Grant soon come to an understanding when they must fight for their survival.
After surviving an encounter with the Tyrannosaurus, Tim followed Grant and Lex through Jurassic Park in an effort to return to the Visitor’s Center. He also survived an electrocution when the power was restored to the fences while trying to climb onto the inhabited side of the Perimeter Fence. Once returned to the Visitor’s Center, both Tim and Lex were left alone so Grant could find the other survivors. Their peace was short-lived, as it was discovered that the Velociraptors had escaped. Tim outsmarted one of the carnivores and trapped it in the freezer and escaped with his sister as Grant and Dr. Ellie Sattler returned. The entire group was saved, incidently, by the Tyrannosaurus as it attacked and killed the two remaining Velociraptor.
Four years later, Tim was seen once again in the mansion of John Hammond as Dr. Ian Malcolm was summoned.
Tim Murphy was played by Joseph Mazzello.