Landfill Beyond the Stars

In Speculative Fiction, you will sometimes find that entire planets get used as interstellar landfills. Implicitly this means that it is somehow worthwhile to launch refuse into space and take it to another planet, possibly one that is located in another solar system, in order to dump it there, rather than give it a push towards the nearest star, or just recycle the stuff (not to mention massive and cheap energy sources that make such launches worthwhile in the first place—just getting into space in the first place is a lot harder than most people think). This is usually a consequence of the fact that Sci-Fi Writers Have No Sense of Scale, treating interstellar space and the different planets like a sea with islands in it rather than as an infinite void with tiny rocks and not-so-tiny furnaces separated from each other by immense distances, an environment where any man-made object would be so tiny as to be insignificant for most purposes.

In many cases, the landfill-planet will even be inhabitable, if only barely, for the convenience of the protagonists who will naturally end up spending time there at some point. Hobo cities built out of scrap optional.

Of course, it never dawns on some to just Hurl It Into the Sun...

For this trope to work at all, the setting must have very Casual (and VERY CHEAP) Interstellar Travel. For this trope in a smaller scale, see Down in the Dumps.

Anime & Manga

 * An episode of the Kirby anime involved aliens trying to turn Popstar into one of these, as part of Dedede paying off his debts. Key word: Trying.
 * The ironically named Shangri-La colony from Gundam ZZ is mostly used as a scrapyard, collecting all the wreckage from the space wars that have been raging intermittently for the past 9 years. Unsurprisingly it's mostly populated by devil-may-care teens who dream of running away to a better world & lots of people with names ending in vowels.
 * In the American manga EV, the robotic alien Evie encounters seems to come from a world like this—specifically, a world based on Junkion from The Transformers.
 * An episode of Doraemon involves how littering is wrong. The gang travel to an Earth-like planet where littering is Serious Business. Gian and Suneo got caught littering and sent work at a disposal site where all garbage is compressed into giant balls and illegally launched into orbit.

Film

 * In the film Soldier the main character had been dumped on a "landfill planet" because he was taken for dead.
 * The Planet of Junk in The Transformers: The Movie is partly an example. While entirely comprised of junk, it is not a sphere so much as part of a crescent, implying that it is an artificial world. Whether the Planet of Junk was built by the Junkions is never actually explained.
 * Star Wars:
 * Raxus Prime.
 * Along with its somewhat interchangeable counterparts Ord Mantell and Lotho Minor.
 * Star Wars averts it with Coruscant. The planet's waste is recycled or composted where applicable, and the truly hazardous, irreclaimable garbage gets packed into containers and shot into orbit, where it gets a subsequent heave toward the sun.
 * The planet Caamas was used as this after the planet was utterly devastated by orbital bombardment. This was something of a charitable endeavour, as the Caamasi were paid for the use of their (now mostly useless) planet.
 * There is a comic where Han Solo crashes on a planet of junked tech and has to salvage parts to rig up something to get off world.
 * In WALL-E, earth itself has become a junk planet, and humanity has gone beyond the stars instead. Not a usual example of the trope, as Earth was not intentionally made such, but the visual aesthetic is the same.

Literature

 * Larry Niven's short stoy "The Woman in Del Rey Crater" involves humanity dumping most of their nuclear waste into a single crater on the Moon. This is actually explained pretty well: the radioactive waste is hideously dangerous NOW, but we may find a way to use it at some later time. The Moon has no environment to damage, is very sparsely populated, and is relatively easy for this near-future society to reach, so it makes an excellent landfill until recycling technology catches up.
 * Garbage World by Charles Pratt. An asteroid is used as the dumping ground for the trash of the pleasure asteroids.
 * In the Red Dwarf novelizations, the Garbage World on which Lister ended up stranded turned out to be.

Live Action TV

 * Firefly:
 * The Expanded Universe has Beylix, essentially a giant storage yard for the United Reclamation company.
 * Also, to some degree, Boros.
 * The '70s sci-fi spoof Quark was set on an interstellar garbage truck, presumably headed to one of these planets.
 * In the "Shatnerverse" corner of Star Trek's Expanded Universe, a resurrected Kirk gets dumped onto a Borg planet used as a holding station for refuse before it's recycled. This is partially explained in that the Borg canonically have easy interstellar "transwarp", but it's still a Class-M planet (inhabited, even) when any random location in space would do, and far less efficient than just recycling on-site.
 * In a different version of this trope, the Malon in Star Trek: Voyager dump their theta radiation in other regions of space whether or not they're inhabited.
 * The setting of a Lexx episode. The system's other planets were mutually annihilated by war, leaving a few hundred employees stranded on the landfill planet. It got worse.
 * Gerry Anderson's Space: 1999 started with the moon being used as a nuclear waste dump.

Tabletop Games

 * The darkly humorous role-playing game HOL: Human Occupied Landfill takes place on one of these planets. It also takes the concept one step further and turns it into a landfill for people: the planet is the Confederation Of World's only prison.
 * Rifts"
 * The Phase World setting has a unique justification: the planet in question is a deliberate social experiment to see what kind of civilization will emerge from such a place. It was set up by a Mega Corp that operated across three galaxies, and a few dimensions besides, and collected debts that were sometimes measured in planets.
 * The Rifts megaverse builder sourcebook also has an entire Landfill dimension. Seems when you can use magic to open Rifts and just dump your garbage it has to all go somewhere.
 * The GURPS setting of Infinite Worlds features Empty worlds, parallel Earths where no intelligent life has evolved, and some where no life has evolved at all. The latter are occasionally used as dumping grounds for hazardous waste. Nonetheless, Homeline's Greenpeace is still opposed to the idea.
 * Given the sheer scale and variety of environments, it's almost impossible for Warhammer 40,000 to NOT have a bunch of these. Interesting twist though: they weren't dedicated trash planets, but rather "hive worlds" that are so overpopulated, overdeveloped and over-mined that they're literally out of obtainable resources, the surface covered in barren rock, polluted (if not boiled-off/siphoned-away) seas and sprawling arcologies that house billions. Many of these worlds subsist on simply scrounging for material in sub-continent-sized piles of industrial refuse, and mass recycling of all water and organic products. Yes, that includes people. The lucky ones that reach this state are able to trade off millions of people a year (or month, or week)) as labor or military in exchange for fresh sustenance, although they of course just squander it away just as quickly.
 * In the anthology module The Vortex of Madness and Other Planar Perils for Dungeons & Dragons, there is the demi-plane of Leonis (named after the archmage who discovered it) a huge junkyard of scrap metal and debris. This is a dumping ground for Mechanus, and while natives of that plane deny this is true (claiming the Plane of Ultimate Law is, by nature, flawless and thus can produce no waste or residue) it has been confirmed by the - admittedly few - inhabitants.
 * Planescape: the Trash Heap is a location in the Para Elemental Plane of Ooze where Sigil - and likely other planar cities - dump all their garbage, the reason being that Ooze is already a disgusting, foul place where only madmen would willingly visit, let alone live. Given that Sigil has been a functional city longer than most Prime societies, the place is the size of a mountain, and continually growing. The numerous scavengers who end up here make this one of the most dangerous parts of the plane.

Video Games

 * Total Annihilation had one of those planets, the moon of one of the factions' capital planet. Good thing about the junk, too. The moon was all mined out to cover the surface of said world in a metal shell, so the wreckage was the only source of war resources.
 * New Junk City, the first level of Earthworm Jim, looks like one of these on the surface,
 * A more reasonable version appears in Mass Effect; the planet Korlus is used as a junkyard/recycling plant for old space-craft, and only those that were near a Mass Relay. It's a dirty and dangerous task due to the various volatile chemicals released during the process.
 * In Escape Velocity, you can take random missions to dump garbage on uninhabited worlds.
 * Stage 2 of Gradius Gaiden, named "Requiem for Revengers". Like the level name suggests, you'll meet the partially-functioning wreckage of past Gradius bosses trapped in the junk.
 * In StarCraft 2, planet D-3794(aka, "Deadman's Rock") comes off as this. A lawless planet far outside of Dominion space, its surface is littered with debris and scrap, even near its two main settlements.
 * Some of the planets in Super Mario Galaxy and Super Mario Galaxy 2 had planets covered in garbage in which the Gearmo living on it wants to get rid of it, and as a result he wants Mario to dispose the garbage by either blowing it up with Bob-ombs or burning it with the Fire Flower in order to give him a star as a reward.

Web Comics

 * Freighter Tales is set on an interstellar sewer tank.
 * In Sluggy Freelance, an alternate universe that's a mashup of Star Trek, Star Wars, and Alien regularly sends ships to a dimensional portal in deep space, where they dump toxic waste into whatever dimension happens to be on the other side.

Web Original

 * The SCP Foundation seems to have found one on Jupiter's moon Io.

Western Animation

 * Planet Dirt from Invader Zim, one of many Irken planets dedicated to a single purpose.
 * The junkyard planet in the Justice League episode "War World."
 * Futurama:
 * One episode has the crew of Planet Express sent to destroy a ball of garbage that was previously thrown into orbit, Armageddon-style. The bomb, however, "misfires", and the Earth resorts to a different tactic: rolling up an identically-sized garbage ball and tossing it at the big ball of trash.
 * Another episode has the characters disposing of electronic waste on "The Third World" (of the Antares system).
 * Megas XLR features one in the episode "Junk In The Trunk", which on the surface looks quite similar to Junkion from Transformers. May be coincidence, although given the number of Shout Outs to Transformers in the series...

Real Life

 * Real World example of the sort of thinking that leads to this trope: the Apollo astronauts jettisoned urine (they said it made a beautiful sight) but were required to store all feces and return it to Earth; apparently the idea of turds in lunar orbit was too much for the mission planners, despite the fact that such matter would quickly desiccate in the cold vacuum.
 * It also makes you wonder: if and when space travel becomes significantly cheaper, can we get rid of garbage by shooting it into the sun? Or better yet, gigantic land-based mass drivers! Space Is Our Landfill!
 * Considering how many bits of old satellites and rockets are drifting around in orbit these days, some might say that's already the case.
 * Though this will probably be done with trash that forms in space, sooner or later (apart from the low orbits, where it's smarter just to direct them to burn in the atmosphere), it'll always be cheaper to bury your garbage in the ground, or recycle it, than to shoot it up from Earth's gravity well. Not to mention that if something goes wrong, there will be tons of potentially hazardous waste raining from the skies.
 * You could shoot the stuff entirely out of the solar system, into interstellar space, for about half of the energy it would take to drop it into the sun.
 * The Soviets had plans to use their Energiya rocket to launch nuclear waste into space (into a safe planned solar orbit, that is) but the plan came to nothing thanks to the fall of the USSR.
 * Having excessive amounts of space junk floating around is becoming a real concern for engineers. Generally, space garbage can either be burnt up in the atmosphere or tossed up into a graveyard orbit, which is beyond a geosynchronous orbit. This isn't a perfect solution, but requires less fuel in some cases, like for satellites in geosynchronous orbits. And that's where the space garbagemen come in...