Erewhon is a novel by Samuel Butler. The title is also the name of a country, supposedly discovered by the protagonist. In the novel, it is not revealed where Erewhon is, but it is clear that it is a fictional country. Butler meant the title to be read as the word Nowhere backwards, even though the letters "h" and "w" are transposed, therefore Erewhon is an anagram of nowhere. The book is a satire on Victorian society.

The greater part of the book consists of a description of Erewhon. The nature of this nation is intended to be ambiguous. At first glance, Erewhon appears to be a Utopia, yet it soon becomes clear that this is far from the case. Yet for all the failings of Erewhon, it is also clearly not a dystopia, such as that depicted in George Orwell's Nineteen Eighty-Four. As a satirical utopia, Erewhon has sometimes been compared to Gulliver's Travels (1726), a classic novel by Jonathan Swift; the image of Utopia in this latter case also bears strong parallels with the self-view of the British Empire at the time. It can also be compared to William Morris' novel News from Nowhere.

Erewhon satirizes various aspects of Victorian society, including criminal punishment, religion and anthropocentrism. For example, according to Erewhonian law, offenders are treated as if they were ill whilst ill people are looked upon as criminals. Another feature of Erewhon is the absence of machines; this is due to the widely shared perception by the Erewhonians that they are potentially dangerous. This last aspect of Erewhon reveals the influence of Charles Darwin's evolution theory.