World Government SF

World Government Sci Fi describes a world, usually Earth but not always, that is governed by a unified body. Generally, it is utilized in conjunction with other sub-genres. As such, World Government can be seen more as a feature of Sci Fi stories than as its own sub-genre.

The idea of a world government has been in circulation for ages in philosophy, fiction, popular culture, and political science. Plato and Kant both theorized about its possibilities. In popular culture world governments are featured in television series (Star Trek's Federation), movies (WALL-E's Buy 'n Large corporation), video games (StarCraft's United Earth Directorate), and anime (Gundam Wing's Earth Federation); Star Wars, a pop culture series of films, also featured an "Imperial"/one world government order that was seeking to control the entire galaxy.

World governments are almost naturally occurring in Sci FI. Many Sci Fi stories that present humanity exploring the solar system also present a unified government on Earth--implying that human exploration of the galaxy requires a single governing body to overcome the challenges involved with galactic expansion. The creation of a world government is a common result of contact with extraterrestrials, especially threatening species. Also, a high number of alien governments are described as world governments.

You can view the crowd-ranked "Popular" World Governement Science FIction book list and vote and/submit entries to it.

1 Starship Troopers

By Robert A. Heinlen. The world is governed by military veterans.
2 The Shape of Things to Come

By H.G. Wells. This story is a frame of future events on Earth, which includes the establishment of a world state as a solution to humanity's problems.
3 The Machine Stops

By E.M. Forster. This is a story about dependence on technology. Most humans have lost the ability to live on the surface of the Earth and below grand, life is governed by an omnipotent machine.
4 Brave New World

By Aldus Huxley. The novel opens in AD 2540 where most of the population is unified under the World State. There is peace, society is stable, and resources are plentiful.
5 We

By Yevgeny Zamyatin. The One State has conquered the world. The One State has a prison-like structure run on maximum efficiency and individuality has been snuffed out.
6 Childhood's End

By Arthur C. Clarke. In this novel the arrival of a seemingly benevolent alien race ends all wars and helps to create a world government.
7 Shadow of the Giant

By Orson Scott Card In this particular novel within the Ender series, Peter Wiggin becomes Hegemon of the whole Earth.
8 Left Behind series

By Tim LaHaye and Jerry Jenkins. A series that takes place after the rapture. The antichrist becomes the leader of the UN and declares a global government, currency, and religion.
9 Last and First Men

By Olaf Stapledon. Within this future history novel, spanning eons, several world governments are established.
10 X-wing: Starfighters of Adumar

By Aaron Allston. Most of the worlds in the Star Wars universe have united world governments because this is necessary to membership in the New Republic. This novel presents the planet Adumar, which does not have a world government, but works towards one.

Other Features of World Government Science Fiction

Level of Real Science
Variable. The realness of science and technology is not a part of the sub-genre's definition. As a result, the level of real science is going to depend on the goals of the writer.
Level of Grand Ideas/Social Implications
High. A story featuring a single body governing the population of an entire planet will necessarily explore the social implications of such a structure.
Level of Characterization
Variable. Character development is not a defining feature of World Government Sci Fi. As a result, characterization is at the discretion of the writer. Of note is the often recurring character type: the Earth President.
Level of Plot Complexity
Moderate. There is no common plotline of World Government Sci Fi. A world with a unified body is relatively complex and so the navigation of events in the story have a similar level of complexity.
Level of Violence
Variable. A world government can create peace and thus eliminate most violence. On the other hand, a corrupt world government may use violence to control its citizens or cause the formation of rebel groups that use violence to fight against the government.

Related Science Fiction subgenres

Utopia and Dystopia.

World governments are a utopian idea, meant to create harmony and end war. However, these governments can easily turn into dystopias.
Social Science Fiction.

Like the Utopia/Dystopia genres, Social Science Fiction might employ a World Government conceit to explore a concept or theme. World Government ideas are sometimes present in Space Opera, though the focus is NOT on the government in this subgenre. Transhumanism might also feature World Government concepts, with society having evolved to a higher level now unified as a single entity or under a single (benevolent) order.
Political Science Fiction.

A political system is part of government, so any World Government story is also Political Sci Fi.