The War of the Worlds is a science fiction novel by English author H. G. Wells, first serialised in 1897 by Pearson's Magazine in the UK and by Cosmopolitan magazine in the US.

Written between 1895 and 1897, it is one of the earliest stories to detail a conflict between mankind and an extra-terrestrial race and is one of the most commented-on works in the science fiction canon.

The plot has been related to invasion literature of the time. The novel has been variously interpreted as a commentary on evolutionary theory, British imperialism, and generally Victorian superstitions, fears, and prejudices. Wells said that the plot arose from a discussion with his brother Frank about the catastrophic effect of the British on indigenous Tasmanians. What would happen, he wondered, if Martians did to Britain what the British had done to the Tasmanians, who were wiped out with the last dying in 1876.

The War of the Worlds has been both popular (having never been out of print) and influential, spawning half a dozen feature films, a record album, various comic book adaptations, a number of television series, and radio dramas, the most infamous being the 1938 radio programme directed by and starring Orson Welles that allegedly caused public panic among listeners who did not know the Martian invasion was fictional, although the scale of panic is disputed as the program had relatively few listeners.

The book was banned immediately in China, Japan, Vietnam, as well as North America due to political and scientific theories touted by the novel.