History Main / PlanetaryNation

* Frequent in the ''Anime/RobotRomanceTrilogy'', where [[Anime/CombattlerV Planet Campbell]], [[Anime/VoltesV Planet Boazania]] and [[Anime/ToshoDaimos Planet Baam]] are all led by one monarchy each. Though, with the last one, the destruction of Planet Baam causes some Baam to follow the son of their former ruler, Richter, while others choose to follow the lead of Erika on [[LaResistance Utopia]].

* ''Franchise/WonderWoman'' [[ComicBook/WonderWoman1942 Vol 1]]: The entirety of Venus is ruled by Queen Desira.

* ''Anime/{{Daltanious}}'': Each planet has one ruling family, such as Helios, Zaal, Marios and Proxia. There are also cases of Royals from different planets marrying and having children. Even the main character is half-Earthern and half-Heliosian.

* Very common in ''Series/DoctorWho''.
** Galiffrey being a prominent example. It's only shown form of government if a counsel that [[Recap/DoctorWhoS23E1TheMysteriousPlanet tried to get the Doctor on trial]] and [[Recap/DoctorWhoS30E17E18TheEndOfTime much later try to destroy the entire universe]].

* ''Anime/BraveRaiden'': The Demon Empire is led by Emperor Barao, and it's implied that their political system is a monrachy as he's [[AmbiguouslyRelated more or less related]] to Prince Charkin.

* ''Anime/{{Gigantor}}: The Demon Empire[[note]]No relation to the one from ''Anime/{{Raideen}}''[[/note]] is led by King Uchuumaoh. While he isn't from a Royal Family himself, he was once a human who was corrupted by a black hole, and gained immense power as a result. This also led to him acquiring many dedicated followers who joined his empire.

If ''Earth'' is this, see OneWorldOrder. The aversion is MulticulturalAlienPlanet.

* This is nearly always true in the ''Franchise/StarWarsExpandedUniverse''. One of the few exceptions is the planet Adumar in ''[[Literature/XWingSeries X-Wing: Starfighters of Adumar]]'', which contains several competing alliances of nation-states. The New Republic and Empire start out negotiating with the most powerful one without fully understanding this, leading to problems. Another occurs in a young adult novel with Obi-Wan Kenobi as a Padawan, when he goes on a mission to a planet in the midst of a centuries-old civil war. They can't even agree on the planet's ''name'', with the Melida and Daan factions both naming it after themselves, so the Republic calls it Melida/Daan.
* Most of the nations, planets and Space Stations in the ''Literature/VorkosiganSaga'' are this. The few exceptions are the Cetagandan Empire and Barrayaran Empires, which are nations made up of ''multiple'' planets, and Earth, which is still split up into a gillion countries like today. Jackson's Hole is made up of numerous Great and Minor Houses, which are functionally countries in their own right.

*** The Solarian League includes an almost uncountable number of star systems and is described, only partially ironically, as "the heir to all mankind's greatness". It's also so bogged down by corruption and bureaucratic red tape that it's essentially ungovernable, and by the time of the main story is falling apart at the seams.
* This is actually the law for colonies in ''Literature/TheGenesisFleet'', where colony permits are only given out to a single group per planet in order to avoid conflict. This is why everyone shocked when Scatha brazenly establishes a colony on the already-settled planet Glenlyon. This just serves to indicate that there's no one to enforce the rules anymore, after the invention of the jump drive and the second wave of expansion, as Old Earth is no longer interested in being the "big brother", and neither are the old colonies. In fact, Earth is actually mothballing and selling off its SpaceNavy. The trope is definitely averted in the case of Earth, which still has the old nation-states, and Mars, which is largely run by gangs. By the end of ''Vanguard'', the Glenlyon colonists manage to retake their world, kicking Scathans off the planet.

* ''Literature/FoundationSeries'': This is the status of the Terminus Foundation between [[Literature/TheEncyclopedists 50 F.E.]], when the [[GalacticSuperpower Galactic Empire]] withdraws from its region of the galaxy and Mayor Salvor Hardin succeeds in securing Terminus' independence from the surrounding Four Kingdoms, and [[Literature/TheMayors 80 F.E.]], when the Foundation manages to establish political control over said kingdoms, thus establishing what becomes the Foundation Federation (though the Four Kingdoms being ''formally'' integrated into the same state as the Foundation lags considerably behind, with there being references as late as [[Literature/TheMerchantPrinces 150 F.E.]] that suggest the Four Kingdoms are technically still separate from the single-planet Foundation even if they are so dependent as to effectively be an extension). Note that, during this time, the Foundation consists of a single city and the farms surrounding it on an otherwise unoccupied planet, thus making it a LandOfOneCity as well.

** Galiffrey being a prominent example. Its only shown form of government if a counsel that [[Recap/DoctorWhoS23E1TheMysteriousPlanet tried to get the Doctor on trial]] and [[Recap/DoctorWhoS30E17E18TheEndOfTime much later try to destroy the entire universe]].

* Usually the case for human inhabited planets in ''TabletopGame/Warhammer40000''. The Imperium is so large that any given planet is usually ruled by a single governor (how they're chosen, what they are internally called and whether the post is just a figurehead for whatever faction is actually calling the shots varies from planet to planet, though the Adeptus Administratum will officially refer to them as a Governor of the Adeptus Terra regardless of whether its President or King or whatever else internally). They're usually given full control of their planet and left alone, as long as they pay their tithes, make sure the Imperial Cult (or locally approved variation) is worshipped by all inhabitants and don't show signs of sedition (and they don't call for help, although that's usually less effective at getting someone's attention). However, in many cases this is just to make the paperwork easier; there are several planets where the "governor" is whichever ruler or tribal warlord was winning the day Imperial officials last visited, usually technologically regressed Feral and Feudal Worlds. Some Feral World tribals don't even know the Imperium exists.

* Taris from ''VideoGame/KnightsOfTheOldRepublic'' seems not only be a planet with one Government, it seems to be a planet of one ''city''!

* Played with in ''WesternAnimation/{{Futurama}}'' in regards to Earth itself. Earth has its own overarching government ([[AmericaTakesOverTheWorld that is somehow also the American government and based on American governmental traditions]]), but other nations are shown to still exist with their own set of laws. And then its usually played straight when any other planets show up (which is normally OnceAnEpisode).

** Galiffrey being a prominent example. Its only shown form of government if a counsel that [[DoctorWhoS23E1TheMysteriousPlanet tried to get the Doctor on trial]] and [[Recap/DoctorWhoS30E17E18TheEndOfTime much later try to destroy the entire universe]].

* Most planets on ''Franchise/StarTrek'' are examples of this trope. When a planet isn't united, the Federation basically considers it to be in a state of civil war, even if the nations aren’t actually fighting each other. Earth throughout most of its history was presumably in civil war, and (except for some arguable periods of peace) continued to be at least until around 2150 AD ([[MoralDissonance almost nine decades after first contact with the Vulcans ironically enough]]) when the last holdout finally joined [[OneWorldOrder United Earth]]. Some Federation planets (such as Vulcan) have had Planetary Nations virtually into antiquity.

* True in ''WesternAniamtion/{{Ben 10}}'' for basically every single world that isn't earth. Some have one government that covers multiple planets.

* ''Literature/FoundationSeries'': This is the status of the Terminus Foundation between [[Literature/TheEncyclopedists 50 F.E.]], when the [[GalacticSuperpower Galactic Empire]] withdraws from its region of the galaxy and Mayor Salvor Hardin succeeds in securing Terminus' independence from the surrounding Four Kingdoms, and [[Literature/TheMayors 80 F.E.]], when the Foundation manages to establish political control over said kingdoms, thus establishing what becomes the Foundation Federation. Note that, during this time, the Foundation consists of a single city and the farms surrounding it on an otherwise unoccupied planet, thus making it a LandOfOneCity as well.

* ''ComicBook/WonderWoman1942'': The entirety of Venus is ruled by Queen Desira.

* This is nearly always true in the ''Franchise/StarWarsExpandedUniverse''. One of the few exceptions is the planet Adumar in ''[[Literature/XWingSeries X-Wing: Starfighters of Adumar]]'', which contains several competing alliances of nation-states. The New Republic and Empire start out negotiating with the most powerful one without fully understanding this, leading to problems. Another occurs in a young adult novel with Obi-Wan Kenobi as a Padawan, when he goes on a mission to a planet in the midst of centuries-old civil war. They can't even agree on the planet's ''name'', with the Melida and Daan factions both naming it after themselves, so the Republic calls it Melida/Daan.

*** The People's Republic of Haven, at its height, is stated to have over three ''hundred'' star systems under its umbrella, most by forced conquest. One MeaningfulRename and [[BoomHeadshot dramatic governmental reorganisation later]], it sheds over half of those, the rest remaining voluntarily and by their own request.

* Usually the case for human inhabited planets in ''TabletopGame/Warhammer40000''. The Imperium is so large that any given planet is usually ruled by a single governor (how they're chosen and whether the post is just a figurehead for whatever faction is actually calling the shots varies from planet to planet). They're usually given full control of their planet and left alone, as long as they pay their tithes, make sure the Imperial Cult (or locally approved variation) is worshipped by all inhabitants and don't show signs of sedition (and they don't call for help, although that's usually less effective at getting someone's attention). However, in many cases this is just to make the paperwork easier; there are several planets where the "governor" is whichever ruler or tribal warlord was winning the day Imperial officials last visited, usually technologically regressed Feral and Feudal Worlds. Some Feral World tribals don't even know the Imperium exists.

* Usually the case for human inhabited planets in ''TabletopGame/Warhammer40000''. The Imperium is so large that any given planet is usually ruled by a single governor (how he's chosen varies from planet to planet). They're usually given full control of their planet and left alone, as long as they pay their tithes and don't show signs of sedition (and they don't call for help, although that's usually less effective at getting someone's attention). However, in many cases this is just to make the paperwork easier; there are several planets where the "governor" is whichever ruler or tribal warlord was winning the day Imperial officials last visited.