A Hive City is a Mega City, but whereas most mega cities look pretty much like our modern cities although spread over a larger area or with way more tall buildings, a Hive City is not built up of individual buildings but is in fact one gigantic building. In many ways, it's more akin to an anthill or a hive than to a standard modern day city.
Some hive cities started out as regular mega cities or skyscraper cities but then built generation after generation of buildings on top of each other until they all interlinked into one. Another case is that the city is built in a poisonous environment or vacuum and thus must be a closed environment. Or the people who built it were not human and simply had a very different mindset than humanity when it comes to housing. If it's the last case, it may be inhabited by Bee People.
Sub-Trope of Mega City. Supertrope of Arcology, where a hive city is a self-contained system. May overlap with Layered Metropolis. In extreme cases, it may be large enough to qualify as a City Planet.
- Girls' Last Tour: Before an unspecified apocalyptic event destroyed it, urban civilization expanded exponentially, covering most of the surface world and then building vertically upon itself. The ruined cities that the girls explore consist of multiple stacked levels as a result, often consisting of buildings so large that they spend hours traveling through some of them, and considerable time and effort is needed to cross through the multiple layers of a single city.
- In Hallucinations from the Womb, a short story collection by Mohiro Kitoh, the setting of Shell City is one of these. It builds up on itself over the years, and the lower layers are completely buried.
- Aeon 14: Space stations tend to be gargantuan constructions with more human-sized buildings within them. One prime example of this is the Cho (short for "Callisto Orbital Habitat"), a city-state in the Sol system consisting of a series of concentric rings that were constructed around Jupiter's moon Callisto beginning in 3245 CE. Ring 1 was attached directly to the moon and the others were built outward from it over succeeding centuries. As of Outsystem's date of 4123 CE, the Cho consists of 151 rings and has a population of over three trillion people, comprising almost half of all humans in existence at that time. The Cho is so big it blocks nearly all view of space from the surface of the moon itself, which was once terraformed but has been reduced to waste-processing for the Cho.
- The Caves of Steel: Earth's population lives in eight hundred immense, domed "Cities" with an average population of around eleven point two million, which the growing pressure to utilize the enclosed land as efficiently as possible has filled with extremely dense urban growth. The result is that each city has become a forest of windowless, interconnected towers hundreds of stories high and of buildings larger than modern city blocks. Their inhabitants spend their entire lives enclosed within these giant sprawls of architecture, to the point that they've started to develop an aversion to open spaces and even windows — an echo of the more pronounced habits of their City Planet-dwelling descendants in the Empire and Foundation novels. This is in contrast to the Spacers of the offworld colonies, who live in exponentially less dense populations and like to spread out where Earth folk build close and high — the Spacer neighborhoods in Earth cities consist of single houses and cultivated land each under its own dome, a practice that the Earth natives find very bizarre.
- The Cinder Spires: The Spires are Star Scrapers constructed by the Builders out of an unknown stone to house all humanity. Each Spire is a nation unto itself, with individual habitation levels acting like provinces and human (and cat) habitation built inside.
- The Corsay Books: The city of Trowth was created when a noble family built a tall, spindly tower with a view of the river, which offended another noble family who made a squat ugly tower in front of the tall spindly tower as an insult. This escalated into a war of constant tower-building, which expanded into a new front when one architect built bridges over a major thoroughfare that went through his property. Soon, people started building on top of the bridges, and adding further levels above those, and building on top of that, leading Trowth to become a massive, towering, constantly constructed mountain of architecture whose lower levels are shrouded in constant gloom.
- Hive Mind (2016): The Hives are of the deliberately-constructed kind. Hive England, where the main characters live, holds 100 million people in 10 zones, with 100 residential levels and 50 industrial levels above that. There are one hundred and seven Hives in all, where humanity almost exclusively lives; it is unclear whether Hive England is relatively large, small, or in-between.
- Realm of the Elderlings: In the final book of the Tawny Man Triology, the elderlings' city on Aslevjal appears to be this, but it is hardly surprising considering that the elderlings appear to have a beehive-like structure of their society with a single queen and many male drones. It's notable however that the city that Fitz visits in the mountains is not this, despite being said to be a city of the Elderlings.
- Shadowrun: The Kowloon Walled City still exists in the game's timeline (after the real one was torn down, the Shadowrun one was retconned as having been rebuilt to host refugees from a Chinese civil war). Thanks to the advent of magic, the place is even worse than its real-life version, with stagnant qi causing its residents collective despair to pool and attracting the Yama Kings to feast on all the bad vibes.
- Traveller: The Hivers were so named by human explorers who compared their cities to insect hives. It was suggested that they had a Hive Mind, but this was later retconned.
- Warhammer 40,000: The Imperium's hive cities are the trope namer. These enormous cities cover large areas like anthills, and the lower parts are so broken down and toxic that they aren't safe for human habitation any longer (mutants, outcasts and giant spiders like it just fine). And most inhabitants of a hive city never see the light of day. Only the nobles in their spires have that luxury.
- Beneath a Steel Sky: Union City is a sprawling vertical metropolis composed of a network of spires, whose highest quarters, which house the heavy industry, rise well above the cloud tops. Residential areas are beneath these factories, and the city's ultra-rich are below that as well, on the ground level, which somehow manages to be the most aesthetically pleasing region with plentiful sunlight and greenery.
- Final Fantasy VII: Midgar is Shinra Electric Power Company's greatest achievement and primary headquarters, taking the form of a three-layered, city-sized structure powered by no less than seven Mako reactors (Magitek nuclear power plants) that houses the majority of the corporation-country's population. It's a miserable place to live, being choked with urban blight above and below, and the lower levels don't even receive natural sunlight. Shinra plans to build an even bigger, better version, Neo-Midgar, once they find the Promised Land.
- Mass Effect: The Citadel can be considered this, although correctly speaking it's a space station rather than a building. Note that each of the Ward arms is in their own right a skyscraper city, that's how massive this station is.
- Paradise Cracked is set in a Crapsack World where pollution and environmental destruction forces humans to live in such cities. The poor inhabit the lower levels, while the rich live lavishly in the upper levels dubbed HighTown.
- Pokémon Omega Ruby and Alpha Sapphire: Mauville City was a conventional city in the original Ruby and Sapphire, but is converted into one massive building in the remake as a project undergone by Greater Mauville Holdings, something that Wattson attempted to do in the original games but failed to complete, with paved hallways taking the place of city streets.
- Star Ruler 2: Megacities, available as a mid-game research item, are an exaggerated version of this. They're vast metropolises that stretch from the sky to the mantle and can cover entire continents. In the original game, cities can become mindbogglingly dense jungles of steel as the Lensman Arms Race progresses, resulting in more and more efficient forms of urban planning, causing population density to skyrocket.
- Sunless Skies has the Brabazon Workworld, where it's very hard to tell where one building ends and another begins.
- Schlock Mercenary: As explained in this stip, there are roughly 200 billion sophont beings living on Earth, and the immense population is managed by restricting it to a series of immense systems of arcologies and vertical cities that collectively occupy only 10% of Earth's land and oceans but which are several kilometers high and deep. Population density is measured in people per cubic rather than square kilometer. This is viable chiefly thanks to a number of futuristic technologies, including highly efficient underground farming and superstrong construction materials.
- Most proposed human settlement on the Moon or Mars is this, though on a much smaller scale.
- The largest examples of an Arcology are effectively hives, with the additional requirement of the whole structure be at least energy neutral if not entirely self-sufficient.
- Gunkanjima, an island near Nagasaki, Japan where there was a coal mine from 1887 to 1974. The whole island is basically one humongous single building.
- Kowloon Walled City was a former military outpost outside Hong Kong that became a lawless enclave due to it belonging to China but being surrounded by British territory. It became so densely populated with people escaping the law, refugees, and anarchists that it seriously approached this trope featuring high rises fused together and numerous alleyways completely covered by buildings. Before it was finally knocked down in preparation for the return of Hong Kong to Chinanote , it looked to be one monolithic shoddily built building.
- The Palatine Hill in Rome, Italy, where the Imperial Palace resided, and which was built into a hive city over the course of 600 years.
- Old London Bridge makes this trope Older Than Steam. For over five hundred years the bridge had buildings built on it. Much like the Kowloon Walled City, the structure looked like two gigantic fused buildings, with a small break in the middle for the drawbridge. At one point there were well over five hundred buildings recorded there. It had a less than favorable impact on the bridge's utility as, well, a bridge, and the structures were demolished along with that incarnation of the bridge some decades later.
- The Publeoans traditionally live in villages, each of them being a multi-storied mud building surrounding a plaza.
- In Çatal Höyük, a city in Anatolia built during the VIIth millenium, no streets separated the houses, which were all crammed together.