The utopia and its offshoot, the dystopia, are genres of literature that explore social and political structures. Utopian fiction is the creation of an ideal world, or utopia, as the setting for a novel. Dystopian fiction is the opposite: creation of a nightmare world, or dystopia. Many novels combine both, often as a metaphor for the different directions humanity can take in its choices, ending up with one of two possible futures. Both utopias and dystopias are commonly found in science fiction and other speculative fiction genres, and arguably are by definition a type of speculative fiction.

More than 400 utopian works were published prior to the year 1900 in the English language alone, with more than a thousand others during the twentieth century.

The word utopia was first used in this context by Sir Thomas More in his 1516 work Utopia. The word utopia resembles both the Greek words "no place", "outopos", and "good place", "eutopos". In his book, which was written in Latin, More sets out a vision of an ideal society. As the title suggests, the work presents an ambiguous and ironic projection of the ideal state. The whimsical nature of the text can be confirmed by the narrator of Utopia's second book, Raphael Hythloday. The Greek root of Hythloday suggests an 'expert in nonsense'. An earlier example of a Utopian work from classical antiquity is Plato's The Republic, in which he outlines what he sees as the ideal society and its political system. Later examples can be seen in Samuel Johnson's The History of Rasselas, Prince of Abissinia and Samuel Butler's Erewhon, which nearly spells 'nowhere' backwards. This, like much of the utopian literature, can be seen as utopian satire which is most notable in the inversion of illness and crime which Butler portrays, with punishment for the former and treatment for the latter.