Reception to Fahrenheit 451 has been mixed. While praising the book for its effective prose style and handling of important social issues, several aspects of the work have been criticized. Obscure references, such as those to the Phoenix myth and the sixteenth-century martyr Master Ridley, have been faulted for being inappropriate for general readers. References such as these and the novel's emphasis on the value of literature over that of mass culture have also led to attacks on Bradbury for being an elitist. Another area of criticism is that the author pits intellectuals against ordinary people. The book people, represented mostly by scholars, will save humanity, while ordinary people like Mildred contribute to the degradation of society by falling victim to social conformity.

In spite of these criticisms, many analysts find a great deal to praise in the book. John Colmer, in an essay in Coleridge to Catch-22, is struck by Bradbury's ability to convey horror. Bradbury is successful "in creating the horror of mechanized anti-culture," Colmer believes. "The burning scenes have intense power and the pursuit of Montag by the Mechanical Hound … is in the best tradition of Gothic pursuit; mysterious, but relentless," the critic adds. Colmer, though, is one of the critics who finds Bradbury's allusions to culture forced and sentimental. "Bradbury cannot rely on his readers picking up his allusions. He … explain[s] laboriously." He continues: "A writer who has to explain all his allusions and symbols for the benefit of lowbrow readers is at a considerable disadvantage." Colmer does find the message of Fahrenheit 451 important, that "books create diversity and harmony," he explains. As a result the novel "is an intensely serious work of popular Science Fiction."

A major area of praise for Bradbury's work is his style. In his essay in Ray Bradbury, David Mogen claims that Fahrenheit 451 and the collection The Martian Chronicles are "destined to survive as Bradbury's best-known and most influential creations, the most sustained expressions of his essentially lyrical treatment of science-fiction conventions." While Mogen acknowledges the criticism of sentimentality and vagueness in Fahrenheit 451, he maintains that the work "remains one of the most eloquent science-fiction satires, a vivid warning about mistaking" mindless happiness for progress. Mogen also praises Bradbury for his ability to use the fireman as a central metaphor in the story.

In discussing the development of Montag in his essay Ray Bradbury, Wayne Johnson finds that the premise of a fireman starting rather than putting out fires is "farfetched." Johnson adds, however, that Bradbury "keeps such a tight focus on the developing awareness of fireman, Guy Montag, that we can successfully overlook the improbability of his occupation." Johnson praises Bradbury for maintaining "a certain detachment in the book, so that basic themes … can be developed and explored without becoming either too realistic or too allegorical."

The thematic elements in Fahrenheit 451 have received much praise. "Bradbury's rage against censorship and book burning reached its fullest and most eloquent expression … when he expanded 'The Fireman' to novel length," says George Guffey in an essay in Coordinates: Placing Science Fiction and Fantasy. Gary K. Wolfe, in his essay on Bradbury in the Concise Dictionary of American Literary Biography, praises Fahrenheit 451 as a "passionate attack on censorship … equally an attack on the growing power of mass culture, particularly television … which consistently falls prey to the demands of special interest groups." Wolfe observes that the "new culture" of the book people "seems to care as little for the individual as the mass culture from which Montag has escaped," but "the new society allows for a multiplicity of viewpoints and hence holds out some hope for the eventual revival of the human imagination." It is the glimmer of hope that Bradbury presents which has earned him the label of optimist. "Bradbury's novel does risk lapsing at the very close into a vague optimism," writes Donald Watt in his discussion of Fahrenheit 451 as a dystopia (a work presenting a dehumanized society) in Ray Bradbury.

Among the highest praise Bradbury has achieved for his work is the recognition of his stylistic excellence. "On the whole, Fahrenheit 451 comes out as a distinctive contribution to the speculative literature of our times, because in its multiple variations … it demonstrates that dystopian fiction need not exclude the subtlety of poetry," comments Donald Watt. "Bradbury is above all a humanist … ," says Wolfe. "Whatever the final assessment of Bradbury's later work, his historical importance both in popularizing science fiction and making it respectable cannot be denied," Wolfe writes in Twentieth Century Science-Fiction Writers.