Published in 1984, Empire of the Sun was highly acclaimed by critics and became a bestseller in England. In their review of the novel appearing in Newsweek, David Lehman and Donna Foote place the book "on anyone's short list of outstanding novels inspired by the second world war...[It] combines the exactness of an autobiographical testament with the hallucinatory atmosphere of twilight-zone fiction."

Most reviews focus on the novel's serious subject matter. John Calvin Batchelor, in his essay, "A Boy Saved by the Bomb" in The New York Times Book Review, asserts that Ballard "has reached into the events of his childhood to create a searing and frightening tale of wartime China. Yet this novel is much more than the gritty story of a child's miraculous survival in the grimly familiar setting of World War II's concentration camps. There is no nostalgia for a good war here, no sentimentality for the human spirit at extremes...He aims to render a vision of the apocalypse, and succeeds so well that it can hurt to dwell upon his images."

In his review of the novel for The New York Times, John Gross contends that the book "sets out to raise large issues and stir deep feelings, and for the most part it succeeds remarkably well." After criticizing what he considers to be Ballard's editorializing at the end of the book, Gross claims "that is the only real weakness in an outstanding novel."

Gross also praises the novel's style: "The detail of life both in the city and in the camp is brilliantly rendered by Mr. Ballard—with swift, economic strokes where there could easily have been clutter, with a plain, terse style where rhetoric would have been counterproductive."

In Books and Bookmen, William Boyd claims that "what makes [this] Ballard's best novel is that on this occasion style and narrative fuse." Boyd praises the author's pace, structure, character development and use of symbols. While he asserts that the novel contains "flaws" like "shaky" dialogue and repetition in some parts, he states that "the mix is otherwise extremely—and uniquely in his work—impressive."

Many critics maintain that the novel has strong ties to the science-fiction genre. Lehman and Foote note that the novel has earned Ballard the kind of critical acclaim denied his earlier work, "since it has more in common with them than immediately meets the eye. Like its predecessors, the book explores the zone of 'inner space' that Ballard sees as 'the true domain of science fiction.'"

Although the novel is clearly more realistic than Ballard's past work, Gross "still hesitates to call [it] a conventional novel...because many of the scenes in it are so lurid and bizarre, so very nearly out of this world. Among other things, they help to explain why in his work up till now Mr. Ballard should have been repeatedly drawn to apocalyptic themes."

Considering Ballard's future, David Pringle in Earth Is the Alien Planet: J. G. Ballard's Four Dimensional Nightmare determines that "Ballard's reputation will grow in the decades to come, and he is likely to become recognized as by far and away the most important literary figure associated with the field of science fiction. More than that, he will be seen as one of the major imaginative writers of the second half of the 20th century—an author for our times, and for the future."