Utopian and dystopian fiction are subgenres of speculative fiction that explore extreme forms of social and political structures. A utopia is a setting that agrees with the author's ethos, having various attributes of another reality intended to appeal to readers. A dystopia offers the opposite: the portrayal of a setting that completely disagrees with the author's ethos. Some novels depict both types of society to more directly contrast their properties. Both utopias and dystopias are commonly found in science fiction and other types of speculative fiction.

More than 400 utopian works in the English language were published prior to the year 1900, with more than a thousand others appearing during the 20th century. This increase is partially associated with the rise in popularity of science fiction and young adult fiction more generally, but also larger scale social change that brought awareness of larger societal or global issues, such as technology, climate change, and growing human population. Some of these trends have created distinct subgenres such as climate fiction, young adult dystopian novels, and feminist dystopian novels.

Utopian Literature sets itself aside as a literature form of utopian thought and desire. Its characteristics can be described as the thought of a better or ideal society compared to current society, these ideas being formed into a literary medium, the overall concept of utopian ideas encourages the reader to act towards bettering their current society or moves them to understand and recognize current issues critically, and that utopian thought emerges from the desire for a better life and society.

The word utopia was first used in direct context by Thomas More in his 1516 work Utopia. The word utopia resembles both the Greek words outopos ("no place"), and eutopos ("good place").

Thomas More's 1516 book Utopia, written in Latin, 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 the name "Hythloday" suggests an 'expert in nonsense.' Thomas More's idea of a utopia stems from the current economic and societal issues in Tudor England. More directly confronts the issues of rising population, oppressive landlords, and civilians turning to crime through Hythloday's perspective in Book I of his novel.

An earlier example of a Utopian work from classical antiquity is Plato's Republic, in which he outlines what he sees as the ideal society and its political system. Later, Tommaso Campanella was influenced by Plato's work and wrote The City of the Sun (1623), which describes a modern utopian society built on equality. Other examples include Samuel Johnson's The History of Rasselas, Prince of Abissinia (1759) and Samuel Butler's Erewhon (1872), which uses an anagram of "nowhere" as its title. This, like much of utopian literature, can be seen as satire; Butler inverts illness and crime, with punishment for the former and treatment for the latter.

One example of the utopian genre's meaning and purpose is described in Fredric Jameson's Archeologies of the Future (2005), which addresses many utopian varieties defined by their program or impulse. He describes the fundamental dynamic of utopias lying in "identity and difference." Jameson states that the core of utopian thought and politics lies in an imagined system that is thoroughly different from an original, real one.

Another early work of utopian but satirical fiction would be the English philosopher and writer Margaret Cavendish’s The Description of a New World, Called the Blazing World (1666). This is an early example of what would later be called science fiction writing. There is debate about to what degree Cavendish's work can be called feminist. For example, Rachel Trubowitz describes A Blazing World as a feminist utopia due to how much it challenges traditional gender roles; however, Sujata Iyengar says that Cavendish’s work reinforces ideas of racial and feminine inferiority. Vanessa Rapatz focuses more on Cavendish's subsequent impact and argues that her writings provide a context for understanding contemporary feminist authors such as Toni Morrison and Octavia Butler. Because Cavendish often broke the boundaries of conventional female writing and behavior, many people have been dismissive of her utopian vision. Samuel Pepys described Cavendish as being a “mad, conceited” and “ridiculous woman”. Virginia Woolf wrote that her work lacked discipline and “her ideas [were] poured out higgledy-piggledy in torrents of prose, poetry, and philosophy.”