Editing Megastructure (section)

==Fictional==
A number of structures have appeared in fiction which may be considered megastructures.

===Stellar scale===
* The [[Dyson sphere]] has appeared in [[Dyson spheres in popular culture|many works of fiction]], including the ''[[Star Trek]]'' universe.
* [[Larry Niven]]'s series of novels beginning with ''[[Ringworld]]'' centered on, and originated the concept of a ringworld, or Niven ring. A ringworld is an artificial ring with a radius roughly equal to the radius of the Earth's orbit (1 [[Astronomical unit|AU]]). A star is present in the center and the ring spins to create [[g-force]]s, with inner walls to hold in the atmosphere. The structure is unstable, and required the author to include workarounds in subsequent novels set on it.
* In the [[manga]] ''[[Blame!]]'' the megastructure is a vast and chaotic complex of metal, concrete, stone, etc., that covers the Earth and assimilates the Moon, and eventually expands to encompass a volume greater than the orbit of Jupiter.
* In ''White Light'' by [[William Barton (writer)|William Barton]] and [[Michael Capobianco]], a [[Topopolis]] is presented as taking over the entire universe.
*In the [[Heechee Saga]] series by [[Frederik Pohl]], a race of pure energy beings called The Foe have constructed the Kugelblitz, a black hole made of energy and not matter.
* In the [[Xeelee Sequence|Xeelee series]] of books by [[Stephen Baxter (author)|Stephen Baxter]], the eponymous alien race constructed the [[Ring (Stephen Baxter novel)|Ring]], a megastructure made of [[cosmic string]]s, spanning over 10 million light years.
* In ''[[Freelancer (video game)|Freelancer]]'', The Dom'Kavosh's Dyson shell that is inhabited by a drone race created by the Dom'Kavosh, Nomads. This is reached via a hyper gate, created by the same creators as the Dyson sphere.
* The [[Saga of Cuckoo]] series novel ''[[Wall Around a Star]]'' mentions a proposal to build a super dyson sphere, completely enclosing the [[Galactic Center]].
* The title of the novel ''Helix'' by [[Eric Brown (writer)|Eric Brown]] directly references a stellar-scale helical megastructure. Different types of environments and habitats are interspersed along the structure, while their varying distance from the central star affects the climate.
*The player's central quest in computer game [[Dyson Sphere Program]] is to construct a [[Dyson sphere]]. Gameplay focuses on constructing planetary scale factories as a means towards this end.
* The Quarg in the game Endless Sky are shown building a massive ring around one of their stars, which is most likely around one astronomical unit in diameter. A completed version of this can also be found in another location.
* In computer games [[Space Empires IV]] and [[Space Empires V]], the player can construct sphereworlds and ringworlds around stars.
* [[Dennis E. Taylor]]'s 2020 novel ''Heaven's River'' features a ''[[Topopolis]]'' built around an alien system. Different segments of the structure are built with artificial climate and weather.

===Planetary and orbital scale===

* Several structures from the fictional ''[[Halo (series)|Halo]]'' universe:
** The original twelve [[Halo (megastructure)|Halos]], seen in ''[[Halo: Cryptum]]'', were 30,000 kilometers in diameter; a separate array of six Halos are 10,000 kilometers in diameter, with one of the original twelve later being reduced to this size in ''[[Halo: Primordium]]''.
** The Lesser Ark is a 127,530&nbsp;km diameter structure from which the Halo Array can be activated and capable of building 10,000&nbsp;km Halos. The "greater" Ark, seen in ''Cryptum'' and ''Primordium'', is capable of producing 30,000&nbsp;km Halos. 
** Onyx is an artificial planet made entirely out of Forerunner Sentinels (advanced replicating robots). At its core is a "shield world", contained within [[Slipstream (science fiction)|slipstream]] space, that is approximately one [[astronomical unit]] in diameter. The much smaller Shield World 0459, (approximately 1,400&nbsp;km in diameter), is the setting for the latter half of ''[[Halo Wars]]''. A third shield world, Requiem, is the primary setting for ''[[Halo 4]]''.  Requiem is an artificial hollow planet encased in a kind of Dyson Sphere. ''[[Halo 5: Guardians]]'' introduces a fourth shield world, Genesis.
** ''High Charity'', the Covenant's mobile planetoid station.
*In the ''[[Doctor Who]]'' episodes ''[[The Stolen Earth]]'' and [[Journey's End (Doctor Who)|''Journey’s End'']], a planet-sized space station known as The Crucible is built by the Daleks, a genocidal alien race, and facilitates the reality bomb, a weapon meant to erase the entire multiverse from existence. The Crucible also held enough Daleks to slaughter the universe they were in even without the bomb, according to [[The Doctor (Doctor Who)|The Doctor]].
* In ''[[Sonic Adventure 2]]'' and ''[[Shadow The Hedgehog (video game)|Shadow The Hedgehog]]'', the Eclipse Cannon is a planet-destroying WMD built inside of the Space Colony Ark. 
* [[Buster Machine III]] from ''[[Gunbuster]]''.
* The [[Orbital (The Culture)|Culture Orbital]] from ''[[The Culture]]''.
* In the 2013 CGI [[anime]] film, ''[[Space Pirate Captain Harlock (film)|Space Pirate Captain Harlock]]'', the Jovian Accelerator is an ancient, Death Star-like [[weapons of mass destruction|Weapon of mass destruction]] that uses energy from [[Jupiter|Jupiter's]] atmosphere to create a large beam of intense light strong enough to destroy an entire planet.
* [[Knights of Sidonia|Sidonia]], the main ship and home of millions of humans, 1000 years in the future in the Knights of Sidonia manga and anime series, created after the destruction of the earth along with other unnamed seed ships.
* [[Trantor]], the capital of an interstellar empire in [[Isaac Asimov]]'s [[Foundation (book series)|Foundation series]], is an [[ecumenopolis]], a planet entirely covered in one huge metal-clad building, with only one small green space: the Emperor's palace grounds.
* The [[Ori (Stargate)|Ori]] [[Supergate (Stargate)|Supergate]] seen in a number of episodes of ''[[Stargate SG-1]]'' could be classed as a megastructure.
* In ''[[The Hitchhiker's Guide to the Galaxy]]'' series, Earth, as well as other planets, were artificial megastructures. Earth was intended to function as a gigantic computer and was built by a race of beings who made their living by manufacturing other planets.
* Mata-Nui in the ''[[BIONICLE]]'' franchise is classifiable as a megastructure. In the story, he is a massive robot as tall as a planet, and inside his body, every inhabitant of the BIONICLE Universe (Matoran, [[Toa (Bionicle)|Toa]], etc.) all live, unaware that they live inside a massive, space-traveling entity.
* In the ''[[Robotech]]'' Sentinels novels, Haydon IV is an artificially constructed cyber-planet with android citizens.
* In the ''[[Invader Zim]]'' episode "[[Planet Jackers]]", two aliens surround the Earth with a fake sky in order to throw it into their sun.
* In the 2017 video game ''[[Destiny 2]]'', the fleet of Dominus Ghaul, the ruler of the Cabal Empire, features a massive super-weapon named the ''Almighty'', whose wingspan is said to be as wide as the planet [[Mercury (planet)|Mercury]]. ''Almighty'' links itself to a planetary system's star on the quantum level via an energy beam and breaks it down into usable fuel, warping to another system before the star collapses into a supernova. 
* [[Nightmare (Kirby)|Nightmare]]'s fortress from ''[[Kirby: Right Back at Ya!]]'' can be classified as a megastructure because it is the size of a small planet.
* In several works, Arthur C. Clarke writes about a colossal hollow tube, first described in ''[[Rendezvous with Rama]]'' (1973), and inhabited by different races.
* The Citadel in the ''[[Mass Effect]]'' universe is an enormous space station constructed by an ancient race of machines called the Reapers millions of years before the games in the series. At the time of ''[[Mass Effect 2]]'', its population is 13.2 million.
* In the game ''[[Airforce Delta Strike]]'' a large Space Elevator called the Chiron Lift is used to send supplies out into outer space.
* In the game ''[[Half-Life 2]]'', an alien empire, the [[Combine (Half-Life)|Combine]], invaded earth through the border world Xen. After the combine invaded earth in an event named the ''Seven Hour War'', they created a large tower 2.5 miles tall, the ''Combine Citadel''.
* In the ''[[Warhammer 40,000]]'' series, the Imperial Palace (site of the Golden Throne wherein the Emperor of Mankind is kept alive indefinitely) could be considered a megastructure. The palace is a complex of continent-wide structures with the Golden Throne being located in an area stretching across the whole of the Himalayan mountains.
* In the film ''[[Elysium (film)|Elysium]]'', a luxury space station (a [[Bishop Ring (habitat)|Bishop Ring]]) called Elysium houses the wealthy population of the human species.
* Large rotating space-stations are a staple of science fiction, including [[Arthur C. Clarke]]'s novel ''[[2001: A Space Odyssey (novel)|2001: A Space Odyssey]]'', the battle school from ''[[Ender's Game]]'', and the eponymous ''[[Babylon 5 (fictional space station)|Babylon 5]]''.
* Hollowed asteroids feature in various fiction, such as [[Kim Stanley Robinson]]'s novel ''[[2312 (novel)|2312]]'', [[Larry Niven]]'s ''[[Known Space]]'', and Golden Age SF writers like Clarke and Asimov.
* In the 2022 film ''[[Moonfall (film)|Moonfall]]'', Earth's moon is knocked from its orbit and begins to circle closer to Earth. A conspiracy theorist believes the Moon is a Dyson sphere megastructure and turns out to be correct.

=== ''Star Wars'' (1977 – present, American sci-fi franchise) ===
{{Main|Star Wars}}
* The [[Death Star]] from ''Star Wars'' is 160&nbsp;km in diameter, followed by a second Death Star 200km in diameter. 
* Starkiller Base was constructed from the dwarf planet Ilum, depending on the source it's diameter 660 to 830 km. 
* The Centerpoint Station was a 350&nbsp;km spherical space station at the [[Lagrangian point]] between the planets Talus and Tralus in the [[Corellia]] system. It was a gigantic and ancient hyperspace tractor beam with which an ancient race, known as Celestials, created the Corellia star system. With the help of the tractor beam, whole planets could be moved through hyperspace and arranged into their actual orbits around the central star. On the other hand, the same technology could be used as a weapon to destroy even stars. On the inside of the main sphere, a huge living space called Hollowtown was home to many people in a similar fashion as on the inside of a [[Dyson sphere]].
** A second, smaller megastructure of near-identical design, called Sinkhole Station, was also built shortly after the construction of Centerpoint Station. Its purpose was to maintain the stability of The Maw, a black hole cluster constructed using Centerpoint Station.
* [[Coruscant]] is an ecumenopolis, the planet is entirely covered by and essentially a city.  It serves as the capital of first the Republic and then later the First Galactic Empire.
* The [[Galaxy Gun]], a large [[space station]] designed to destroy entire [[planets]] from across the galaxy could be considered a megastructure because its size is more than seven kilometres long.
* The Star Forge from ''[[Star Wars: Knights of the Old Republic (video game)|Star Wars: Knights of the Old Republic]]''.
* Glavis Ringworld is a ring shaped space station around a star in ''[[The Book of Boba Fett]]''.
* The Core World Kuat was circled by an orbital ring used primarily as a shipyard.
* There are multiple instances of hollowed asteroids, such as Hammer Station and the Eye of Palpatine.

=== ''Stellaris'' (2016 video game) ===
{{Main|Stellaris (video game)}}
* Stellar-Scale Megastructures
** A Dyson Sphere is a megastructure added in the Utopia expansion, capable of producing massive amounts of energy at the cost of rendering the solar system uninhabitable, except for Habitats.
** A Ring World is a megastructure added in the Utopia expansion, offering a solar-system sized habitat equivalent to four massive habitable planets.
** A Matter Decompressor is a megastructure added in the Megacorp expansion to the game and allows the owner to harvest massive amounts of minerals from the cores of Black Holes.
** A Mega-Shipyard is a massive shipyard in orbit of a star, capable of producing ships much faster than average shipyards.
** The Aetherophasic Engine is a megastructure built by crisis aspirants, capable of destroying the entire galaxy as a side-product of allowing the race which constructed it to ascend to the "Shroud", an alternate dimension in the game composed of nearly pure energy
** A Quantum Catapult is a large megastructure built around a pulsar or neutron star that is capable of sending fleets instantly across the galaxy. It however is not completely accurate and thus can send fleets away from their intended destinations.
* Orbital/Planetary Scale Megastructures
** A Science Nexus is a massive orbital science laboratory which expands the empire's science production massively.
** A Sentry Array is a massive orbital station that gives you sight over the entire in-game galaxy.
** Habitats are orbital structures which serve the purpose of a small planet.
** A Mega Art Installation is a megastructure that improves your overall amenities and happiness in your empire.
** A Strategic Coordination Center is a megastructure that Increases your naval capacity, and ship speed, as well as adds several other bonuses.
** An Interstellar Assembly acts as a hub for the game's Galactic Community, increases your diplomatic weight, adds more envoys, and another empire's opinion of you.
** Gateways allow for near-instantaneous travel across the galaxy. In addition, there is a unique form of Gateway called "L-Gates" which link up to an extragalactic cluster of stars.
** Orbital Rings are massive ring structures built around planets that afford extra protection and increase the output of the planet.
** Hyper Relays are large structures that allow ships to jump to identical Hyper Relays in adjacent systems instead of using the existing hyperlane connections, thereby avoiding having to traverse systems at sublight speeds.
* In addition, many megastructures can also generate in "ruined" versions, which the player can later repair.