Grant is the primary protagonist of Jurassic Park: much of the novel is written from his perspective, and most of the scientific background information, especially about dinosaurs, comes from his thoughts, recollections, and analysis. Grant is a professor of paleontology at the University of Denver who became famous in the eighties for his field research on fossilized dinosaur nests in Montana. Despite his preeminence in the field of paleontology, Grant sees himself as quite different from his stodgy, academic colleagues. Rather, Grant is an easy-going "average guy" who does not mind getting his hands dirty. In the face of the crisis that occurs at the park, Grant is the perfect levelheaded, unbiased protagonist. Throughout a series of deadly dinosaur attacks, the only time he ever loses his composure is when he yells at Gennaro to own up to his responsibility and help him find the raptor nest.

Although several characters are annoyed that Hammond invites his grandchildren along for the weekend (including, at one point, Hammond himself), Grant quickly embraces the kids' presence. He is immediately drawn to Tim, the young dinosaur expert, he takes on the role of protecting both Tim and his sister, Lex, when the dinosaurs attack. It is unclear why Grant takes on this role. His wife died years ago, so perhaps he regrets the fact that he does not have any children of his own. Most of his research involves the study of baby dinosaurs, the closest thing to children he has ever had. Alternatively, the affinity Grant feels for the children, especially Tim, may be simply due to the fact that they are, like himself, huge dinosaur enthusiasts.