Dr. Alan Grant (Sam Neill)

A famous paleontologist that is brought to explore the park before it is opened to the public. Grant specializes in nesting dinosaurs and enjoys doing field research. He is down to earth and enjoys spending time with Hammond's grandchildren. Grant is the primary narrator

Dr. Ellie Sattler (Laura Dern) 

Grant's partner on the Montana fossil dig who specializes in paleobotany.

John Hammond (Richard Attenborough) 

The owner of the bioengineering firm InGen who loves dinosaurs. He clones dinosaurs to see if the science is possible, but also to make a profit form his park.

Dr. Ian Malcolm (Jeff Goldblum)

 A mathematician who specializes in the chaos theory. Malcolm wears mostly black and warns Hammond that the park is a bad idea, especially since it goes against nature.

Tim Murphy (Joseph Mazzello)  

Hammond's eleven-year-old grandson. Tim is an expert on dinosaurs and gets the computer system running again. Tim is another narrator, often when the situations heighten to make the novel more suspenseful. (In the movie, Tim is portrayed as the younger brother).

Lex Murphy (Ariana Richards)  

Hammond’s granddaughter and Tim's younger sister. Lex enjoys baseball and teasing her brother, but is often frightened and cries during her experience in the park. (In the movie, Lex is portrayed as the older sister. Lex is a computer hacker who is able to get the computer system up and running again within the park).

Dennis Nedry (Wayne Knight) 

Jurassic Park's computer technician. Nedry is hired by the rival Biosyn Corporation to steal fifteen of the park's dinosaur embryos. Nedry is smart, fat, and his computer hacking is responsible for all the problems in the park.

Donald Gennaro (Martin Ferrero) 

The head of InGen's account with the law firm.Gennaro is nervous about the progress of Jurassic Park and has heard rumors of animals getting off the island. He makes Hammond bring in experts (Grant, Sattler, and Malcolm) to evaluate the park.

Dr. Henry Wu (BD Wong)  

A scientist Hammond hires to clone the dinosaurs. Wu is straight out of graduate school and knows very little about dinosaurs. He is only involved with the park because of the inevitable money and fame such research could bring him.

Robert Muldoon (Bob Peck)

  The park's game warden, formerly a big-game hunter and zoo consultant. Muldoon's job is to keep the dinosaurs from eating people or each other. Muldoon is especially concerned about the raptors, and thinks they should all be terminated.

John Arnold (Samuel L Jackson) 

The head engineer at Jurassic Park, who previously worked with missiles and at amusement parks. (In the movies, name is changed to Ray Arnold).

Dr. Harding  (Gerald R Molen)

  The veterinarian at Jurassic Park