Iceworld is a science fiction novel by American writer Hal Clement.

The novel concerns an interplanetary narcotics agent who is forced to work on an incredibly cold world (from his point of view) — so cold that the atmosphere he breathes, sulfur, is a yellow solid.

Galaxy reviewer Groff Conklin characterized Iceworld as "believable, exciting, and satisfying.

"[1] Boucher and McComas gave the novel a mixed review, saying that while it was "thinly plotted and characterized [and] hardly stirs wonder or any other emotion of good fiction," that Clement had "never done a better job of making plausible and scientifically convincing every detail of the physiology and technology of an alien race .

"[2] P. Schuyler Miller reported that "As an intellectual puzzle, it's top-rank stuff," but concluded that the difficulty in identifying with the alien protagonist would limit the novel's appeal.