Dr. Alan Grant
- A paleontologist famous for his studies of fossilized dinosaur nests in Montana. Grant is athletic and down-to-earth, and takes pride in not being a stuffy academic like many of his colleagues. Although certain characters seem to resent the presence of Hammond's grandchildren, Grant likes children and is quickly drawn to Tim in particular. The majority of the novel is written from Grant's perspective
in-depth analysis of Dr. Alan Grant.
- The owner of the bioengineering firm InGen and a well-known dinosaur fanatic. Hammond spends a decade furiously scrambling to clone dinosaurs, partly out of a sincere love of dinosaurs, but also because he is hell-bent on turning his idea into a huge profit. Hammond's greed often seems to supercede his judgment: the worse things get in Jurassic Park, the angrier he gets at those who want to shut the park down.
in-depth analysis of John Hammond.
Dr. Ian Malcolm
- A mathematician who specializes in the emerging field of chaos theory. Malcolm is part of a new breed of mathematician, with a vibrant personality and a wardrobe that seems to consist only of black. One of the original consultants for Jurassic Park, he has always been skeptical that the idea could work. Once Malcolm actually gets to see the island, his predictions of the park's doom get more and more antagonistic, eliciting Hammond's anger.
- Hammond's eleven-year-old grandson. Tim is an expert on dinosaurs. When the dinosaurs at Jurassic Park start attacking the park's guests, the perspective often shifts Tim to heighten the tension. Tim is noticeably more mature than his sister, making him the more reliable narrator of what happens to the children.
in-depth analysis of Tim Murphy.
- Tim's younger sister. Whereas Tim handles the shocks, scares, and predicaments of Jurassic Park with astonishing grace, Lex is prone to cry or whine when the chips are down. She enjoys baseball and teasing her brother, and her young age and close calls with death make her a very sympathetic character.
- Jurassic Park's computer technician. Nedry is hired by the Biosyn Corporation to steal fifteen of the park's dinosaur embryos. The Biosyn Corporation is perhaps the novel's major antagonist, embodying the evil, negligent possibilities of bioengineering. Nedry is smart, fat, and surly, and, in his dealings with Biosyn, represents the novel's lone antagonist human character. His computer hacking is responsible for all the problems that send Jurassic Park into turmoil.
- The head of InGen's account with the law firm Cowain, Swain and Ross. Gennaro is nervous about the progress of Jurassic Park and has heard rumors of animals getting off the island. He forces Hammond into bringing Grant, Sattler, and Malcolm in to evaluate the park. Nevertheless, Gennaro's firm has a stake in InGen, and as soon as he sees the dinosaurs he starts thinking about all the money he can make.
Dr. Ellie Sattler
- Grant's partner on the Montana fossil dig. Sattler is an attractive, twenty- four-year-old specialist in paleobotany. Though the first half of the novel banters evasively around the idea that Grant and Sattler might be dating, Grant finally reveals to Tim that he and Sattler are not, in fact, romantically involved, as she is actually getting married to a Midwestern doctor sometime in the next year.
Dr. Henry Wu
- A scientist Hammond has hired directly out of graduate school to begin work on developing a dinosaur cloning process. Wu is never very concerned about the animals themselves, and has next to no knowledge about dinosaurs as a species. He is only involved with the park because of the inevitable money and fame such research could bring him.
- The park's game warden, formerly a big-game hunter and zoo consultant. Muldoon's primary task is to keep the dinosaurs from eating people or each other. Irritated that Hammond refuses give him more firepower to handle large species like the tyrannosaurus, Muldoon is more concerned about the raptors, which are totally unmanageable. He thinks they should all be terminated.
- The park publicist who feels annoyed that he must play babysitter to the park visitors.
- The head engineer at Jurassic Park, who previously worked with missiles and at amusement parks. Arnold, confident that he can control the entire park virtually by himself, claims that Malcolm's predictions for the park represent a misapplication of chaos theory.
- The in-house veterinarian at Jurassic Park who treats a sick stegosaurus as the tour group passes by.
- An EPA investigator who visits Grant and Sattler in Montana. Morris is digging up dirt to support his suspicion of Hammond, InGen, and the activity on Isla Nublar.
Dr. Roberta "Bobbie" Carter
- A doctor who works at a medical center in Costa Rica. On duty one night at the beginning of the novel, Bobbie is called to treat an InGen employee who has allegedly been injured in a construction accident. The employee's wounds are suspicious, however, leading Bobbie to believe that InGen is not telling the truth about the accident.
- Dr. Carter's paramedic, who is distressed by the injuries to the InGen employee and thinks they were caused by a hupia.
Mike, Ellen, and Tina Bowman
- A family vacationing in Costa Rica. Tina, the young daughter, is attacked by mysterious lizards on the beach at the beginning of the novel.
- The doctor who treats Tina Bowman in Costa Rica. Dr. Cruz is not an expert on lizards, so he refers Tina's case to Dr. Guitierrez, who is more knowledgeable.
- An American doctor in Costa Rica who believes Tina has been attacked by a basilisk lizard. However, Dr. Guitierrez later finds a carcass of a lizard matching Tina's description. It is not a basilisk, so he sends it to Columbia University for identification.
- A leading world authority on lizards who works at Columbia University.
Dr. Richard Stone
- The head of the Tropical Diseases Laboratory at Columbia University. Dr. Stone analyzes the lizard carcass and concludes it poses no threat of infection.
- A technician at Columbia University who sees Tina's drawing of the lizard that attacked her and identifies it as a dinosaur. Alice's coworkers are unbelieving, however.
- A reckless geneticist who is the head of product development at Biosyn Corporation. Dodgson is the one who hires Nedry to attempt to steal InGen's technology from Jurassic Park.