Tyrannosaurus rex is unique among dinosaurs in its place in modern culture; paleontologist Robert Bakker has called it "the most popular dinosaur among people of all ages, all cultures, and all nationalities". Paleontologists Mark Norell and Lowell Dingus have likewise called it "the most famous dinosaur of all times." Paleoartist Gregory S. Paul has called it "the theropod. [...] This is the public's favorite dinosaur [...] Even the formations it is found in have fantastic names like Hell Creek and Lance." Other paleontologists agree with that and note that whenever a museum erects a new skeleton or bring in an animatronic model, visitor numbers go up. "Jurassic Park and King Kong would not have been the same without it." In the public mind, T. rex sets the standard of what a dinosaur should be.

Tyrannosaurus was first discovered by paleontologist Barnum Brown in the badlands of Hell Creek, Montana, in 1902 and has since been frequently represented in film and on television, in literature, on the Internet and in many kinds of games. Brown himself, despite having discovered many other prehistoric animals for the American Museum of Natural History before and after, always referred Tyrannosaurus rex as "my favorite child". In Brown's own words, Tyrannosaurus rex was indeed "king of the period and monarch of its race... He is now the dominant figure in the Cretaceous Hall to awe and inspire young boys when they grow up."