Feudal Future

"Q: What's the difference between democracy and feudalism? A: In democracy, your vote counts. In feudalism, your Count votes."

Feudalism IN SPACE!!!

Kings and queens, princes and princesses, nobles, courts. . ..

A form of Days of Future Past which can incorporate elements from the High Middle Ages right up to the Victorian Age. The chief characteristic is that social status is legally enacted and hereditary.

Occasionally we are told that the king/emperor is elected, but it makes no difference in their authority. Certainly we never see them running for re-election. (A clever writer could make it like the emperor of the Holy Roman Empire, also elected, but such issues as who are the electors and who is eligible to run never come up.)

(Elected monarchy is fairly common in history, but was generally for life; it matters at the succession, not later.)

Among the commonest societies in Space Opera, Planetary Romance, and other forms of Science Fiction.

Falls into two categories:
 * 1) A planet has such a social structure. Often justified by having technological regression (medieval technology being the lower bound as it can be easily recreated from materials found in nature in an intuitive manner) but may have futuristic technology.
 * 2) A multi-planet, even interstellar society. Always has futuristic technology, of course.

Prone to Medieval Stasis, even though technology is far above medieval level. May also involve anachronistic items from real medieval Technology Levels. Evil nobles may restrict commoners' use of high technology; medical technology is particularly common, but commoners often live lives of drudgery and toil. The extent of which any of it can be considered "feudal" is up for grabs.

Often an excuse to use Medieval European Fantasy tropes in SF. On the other hand, most historical (sedentary) societies have had legal enforceable hierarchies, and many do to this day; democracy has frequently been very ill-thought of, and has, from time to time, deserved it.

Frequently rather benevolent, but may range all the way to Aristocrats Are Evil and Deadly Decadent Court. However, it is seldom explicitly Dystopia; Dystopian authorities tend to be more blatantly kept in place by naked force. This trope covers only societies where social status is legally inherited; 1984, where the children of Party members are theoretically admitted because of an exam, and the children of proles who might qualify tend to vanish before it, does not qualify. Also, under this trope, the royals and nobles draw their authority from the law, where the ruling party of a Dystopia does not acknowledge anything as giving them their power.

Often leaning towards the Romantic end of Romanticism Versus Enlightenment.

In some works, heroes have great ease in converting them to democracies. Partly because writers seem to be unaware of any arguments against democracy, and of the complexity of developing a stable democracy.

Note that every large enough nation is divided into territories for ease of administration, and if a given territory is large enough that elections would take years hereditary governors would be practical, which is the definition of feudalism. So this trope may be Justified in settings without FTL communications or Casual Interstellar Travel. Also note that love of spectacle is a desire not likely to go away and neither is Nepotism and that politics based on some form of kinship or clientage arrangement have been more common then pure republics and this might reasonably continue without a radical change in human nature.

Anime

 * Terra II in Saber Marionette J. The six city-states are modeled after various cultures of Earth-That-Was, one being feudal Japan, and another medieval Italy.
 * Not to mention the ones modeled on Czarist Russia, Imperial China, Nazi Germany, and modern-day America.
 * The Kingdom of Sphere in Yoake Mae Yori Ruriiro na rules the moon. Tensions between them and the Earth Federation are a significant plot point.
 * In Code Geass The Britannian Empire is ruled directly by the Emperor and the royal family. While being an oppressive regime it is certainly not a dystopian future, as the countryside is full of Ghibli Hills.
 * It should be noted that this regime is only oppressive to those it conquers. The homeland is a pretty nice place to live. Also, it doesn't actually take place in the future, calculating the calender of the Alternate History reveals that it takes place in the sixties. Still counts though, because feudalism was pretty much dead by the 20th century in Real Life.
 * In Gundam SEED the 'United Emirates of ORB' have this sort of structure, with the Chief Representative and Prime Minister supposedly being elected from one of the five noble houses, but in reality seems to be a simple hereditary handover until the positions are left vacant due to death or the Chief Representative getting kidnapped.
 * ORB's governmental structure is pretty close to the real life example of Malaysia, whose ruler is elected from (and by) the hereditary kings (or appointed governors in case of governorates) of its member states, though in Malaysia's case the position usually simply rotates on the basis of seniority as per gentleman's agreement between electors, and it depends less on the individual electors' power.

Film

 * In Star Wars, we have Princess Leia, and her mother, Queen Amidala, "recently elected ruler of Naboo". Naboo also has a Prime Minister, so Naboo is probably a constitutional elected monarchy with the Queen acting in a similar role to Elizabeth II of the United Kingdom (i.e., lawmaking and ambassadorial duties).
 * It's eventually expanded by, naturally, the star wars Expanded Universe. Naboo elects a new monarch every couple of years, the monarch is meant to represent the innocence of humanity and as such is often very young, which explains why Amidala was queen at age 14. Also the monarch is usually given a new post when their time to reign is over, monarchs are allowed only one term with Padme Amidala becoming the galactic senator for her planet after her reign as Queen.
 * Leia is actually a princess through her adopted father, Prince Bail Organa of Alderaan.
 * Certainly there is feudalism, but besides it looking futuristic to us simple humans, George Lucas did write "A long time ago..."
 * In earlier drafts of the script, Alderaan was to be the center and capital of the galaxy (now Coruscant), and Leia was probably meant to be related to the emperor by blood in some way.
 * Princess Vespa's home world, the planet Druidia in Spaceballs. They even take the medieval imagery even further with Vespa's father the king dressed like an Old World monarch with crown, ermine cape and sceptre.

Literature

 * In Poul Anderson and Gordon R. Dickson's Hoka stories, the imaginative to the point of autohypnosis Hokas have emulated human societies, and since some have kings and nobles, they emulate them. They have a Victorian Britain with a Hoka Queen Victoria.
 * Marion Zimmer Bradley's Darkover.
 * Edgar Rice Burroughs's Mars
 * John Christopher's Prince In Waiting trilogy. Set mostly in England, centuries after a nuclear-war-like natural disaster. England is a bunch of warring city states ruled by princes, but with a dominant anti-technology religion in which people worship Spirits. Christians are an oppressed minority, and mutants are a lower caste.
 * Christopher's The Tripods trilogy as well, in that case overseen by more technologically advanced aliens.
 * Anne McCaffrey's Pern. In the backstory Pern was colonized by space travelers and the dragons were genetically engineered, but for most intents and purposes Pern is medieval (to the point where biological pest control is considered revolutionary).
 * Andre Norton features a good number in her SF: Ice Crown, Android At Arms, Forerunner Foray.
 * One of David Brin's short stories, The Fourth Vocation of George Gustaf explores the possibility that even in a highly technological society, humans are hard-wired to need royalty; the sentient computer(s) running much of Earth's near-utopian future manipulate George, a highly successful but bored intellectual, into becoming King of Earth by "allowing" him to run a sociological experiment in which he claims to be heir of most of the defunct thrones of Europe and Asia. Then they rewrite the human database with the intention of keeping him on the throne - with no way of proving his original hoax.
 * Justified in Lois McMaster Bujold's Barrayar, in that the eratic nature of wormhole travel isolated their colony before it was properly established, leading to loss of technology and reversion to a semi-medieval culture. Just when the warlords had been united and pacified, the planet was reconnected to the galaxy and promptly invaded by an Evil Empire, forcing them to get modern in a generation. Hence a high-tech, star-travelling culture run by a hereditary aristocracy, complete with oath-bound retainers and servile serfs, and an Emperor constantly watching his back for pretenders and plots.
 * There is a strong suggestion that the system is transitioning to a more democratic system as the old feudal order changes, but so far most of the characters are aristocrats so the focus is on their interactions among themselves.
 * Justified and played with in The Peshawar Lancers. In the future of 2025, the developed world is still trapped in the Victorian Age, embroiled in a power struggle an Indianized British Empire, Damascus-based Caliphate, China-Japan and a Satanic Russian Empire.
 * A number of Russian sci-fi novels portray future Russia as a restored monarchy with prosperous economy. Despite being a monarchy, civil rights are still enforced. This likely stems from the idea that Russian people need a single strong ruler who gets things done and doesn't get bogged down with politics and bureaucracy. The same novels will often portray the US as an empire and/or a Wretched Hive, which may or may not be caused by another civil war.
 * In the Carreras Legions series, the UN, after becoming a true world government for Earth, has over the centuries become this, with hereditary positions and a rather explicit caste system.
 * Theodore Judson's novel The Martian General's Daughter takes place in the late 23. century on an Earth with a massively changed socio-political landscape. The main superpower is the Pan-polarian Empire, which spans most of the northern hemisphere. The empire's society and political philosophy is modelled after many previous eras of history, including the Roman and Greek empires of Antiquity and 18th and 19th century monarchies. Similarly to the writer's previous but unrelated novel, Fitzpatrick's War, the novel mixes high sci-fi technology with a deliberately Steampunkish aesthetic.
 * The atevi in the Foreigner series have a social structure whose closest Earth analogue is feudalism. This is due the the alien psychology of the atevi, making it pretty much impossible for them to have a social structure which isn't feudal-like. The Lost Colony of humans living on their planet still have a democracy.
 * While the post-apocalyptic United States in Julian Comstock is still nominally a democratic republic, in practice it's government is morphed virtually beyond recognition into a blend of neo-feudalism and serfdom. Though the re-emergence of an industrial working class is beginning to challenge said serfdom.

Live Action TV

 * Doctor Who ran across these in The Ribos Operation, The Androids of Tara, The Armageddon Factor and on many more occasions. See also the system spanning version.
 * What the set up in State of Decay.
 * There are a few Feudal Lords (barons, dukes, etc.) on different planets in Firefly. In one episode, Mal goes to a party full of aristocrats and winds up fighting one of them in an old-fashioned sword duel.
 * Another episode features a local Baron hiring Inara to "make his son a man."
 * It makes sense, since even the society of the core planets of The Verse have a lot of visible throwbacks to 19th century culture. While the outer rim planets have a definite Western feel, the members of high society on the core planets evoke Victorian Britain and the American Reconstruction and Gilded Age eras (contemporaries of pretty much the whole Western mythos and its tropes).
 * In Star Trek: The Next Generation, Lwaxana Troi is a daughter of the Fifth House of Betazed, the Holder of the Sacred Chalice of Rixx, and Heir to the Holy Rings of Betazed. Betazed is the name of her planet, and may therefore imply quite high ranking nobility. However, the series did never elaborate on the extent of the actual political power of Lwaxana's family, so for all we know, all this titles might not even impress other Betazoids that much anymore.

Western Animation
"Finn: Pleased to meet you, your highness. Mildwin: I'm not a king. I was democratically elected. Finn: Haha! That's adorable!"
 * Adventure Time is filled with numerous odd kingdoms, mostly ruled by princesses, and comes off feeling like a bizarre fantasy world with randomly anachronistic technology. Word of God, however, states that the Land of Ooo is actually on Earth after a massive war destroys currently society. Pretty much lampshaded in this exchange:

Anime

 * In Mobile Suit Gundam, we know the Zeons are the bad guys because they have hereditary nobility murdered billions with nerve gas and a Colony Drop. Also, they have hereditary nobility.
 * The Zanscare Empire of Victory Gundam takes the feudalism schtick even further. Their entire stated goal is to reinvigorate human society by replacing the increasingly impotent democracy of the Earth Federation with a return to a traditional feudal way of life. Might have actually done some good if it hadn't been for Evil Chancellor Fonz Ka Gatie manipulating things for his own benefit.
 * In Mobile Suit Gundam F91, Cosmo Babylonia is shown as an earlier attempt at pulling off what the Zanscare Empire hoped to achieve. The ruling Ronah family in general believed that a return to a more traditionalist aristocracy would do the Earth Sphere much more justice than the inept Federation.
 * The Jovian colonies by Mobile Suit Crossbone Gundam are not only defacto independent from the Earth Federation but had since become a Social Darwinist monarchy out of the need for survival. Things get better over time though.
 * Tenchi Muyo! Ryo-Ohki, The Jurai Empire, the largest stellar empire in the show, is ruled over by four Imperial Houses, from which the Emperor is 'elected' - it's never explained how they're elected, but the candidate pool doesn't seem to be that big, and generally goes to the most powerful candidate. Or whoever Seto-sama wants....
 * Correction: Whoever Tsunami wants, as it was their agreement with her that gives Juraian royalty their powers. And Seto actually installed just one emperor to the throne—her son-in-law Azusa Masaki Jurai. But then, Tsunami is her granddaughter... well, it's all really complicated.
 * Pretty much all the major powers in The Five Star Stories, though Democracies like the Trun Union are not unheard of. The United Hathuha Republic is a bit of an odd case, as its leader is elected (though not by the general public), but many of its member states have monarchies.
 * Though Trun's president spends more time  than he does actually ruling his country, and Amaterasu Kingdom Demesnes is in fact a federated constitutional monarchy with elected parliaments both on the local and federal levels, which just happens to have monarchies for most of its member nations, and a Physical God for its emperor.
 * The Empire in Legend of Galactic Heroes is basically Prussia in space.
 * Humankind Empire of Abh in the Crest of the Stars is a galaxy spanning polity uniting half of the whole Humanity, but is still has a complicated feudal structure with a three-tiered citizenship, but it is subverted in that this feudal structure is in fact just a rank ladder of civil/military service, and is open to any imperial citizen on the basis of individual merit and promotion.

Film

 * There are a few monarchies in the Star Wars Expanded Universe - the Hapes Consortium is (despite its rather Cyberpunk like name) a hereditary absolute monarchy and major galactic power.
 * An even bigger example is the Legacy-era (set 137 years after the films) Galactic Empire which has evolved into a semi-benign hereditary monarchy.
 * Emperor Palpatine replaced the elected senate with regional governors known as "Moffs" but they were appointed rather than hereditary.

Literature

 * Bunches of star nations in David Weber's Honor Harrington, including but not limited to the Star Empire of Manticore (constitutional monarchy), Grayson (constitutional monarchy with strong theocratic undertones) and the Andermani Empire (absolute monarchy with rather nutty, but competent monarchs). Then again, the whole series is Horatio Hornblower IN SPACE!!! Many other forms of government are also seen, ranging from various forms of republics to corporate-run colonies to so-called Peoples' Republics.
 * Manticore had an interesting Justification for its nobility: The oldest noble families are descended from the original colonists who footed the initial investment for the trip out to the Manticore system, with the Queen's family being descended from the biggest investor.
 * Manticore was initially established as a corporativist society not unlike Beowulf or Mesa, but it had to fall back on feudal structure after The Plague that wiped out more than half of its entire population shortly after the colony foundation. Faced with a need to quickly import a huge number of fresh immigrants, and fearing the erosion of their original investment, the original settlers developed the current feudal system as a way to ensure their political and economical domination. A comparison would be an expanding corporation making a new stock issue but protecting the old interest by giving them first chance to buy preferred shares.
 * To be fair it had been their own planet before and one might at least allow them some claim to have the right to set terms in which to invite immigrants. Furthermore there was no fraud or undue pressure, the terms of the immigration were not intolerable in themselves and while they did establish an ascribed hierarchy they retained rule of law, and a constitutional government. And in any event later immigrants could and did have descendants ennobled for achievements, or married into commoner families, sometimes a noble would resign from the lords to run in the commons, the royal consort always had to be common born and in general there was enough "churn" to make the system livable.
 * Empire of Man/Prince Roger series, by John Ringo and David Weber.
 * Also Weber's The Excalibur Alternative in passing, but there it's justified by the Emperor being an English noble born in the 14th century(yes, it's sci-fi - it's a rather odd story).
 * For that matter, the Empire From the Ashes trilogy. The Emperor is absolute in military matters but a kind of limited monarch in civil. The ships of Battle Fleet are hard-wired to obey not the Emperor, however, but rather a massive supercomputer orbiting the capital, leaving him largely impotent if he is voted out of office until a new Emperor can be put into power. This was arranged by the first emperor (elected by the Senate to stop the civil wars) as a check against absolute power, and nothing short of complete reassembly of the supercomputer's core can change its mind.
 * Jerry Pournelle and Larry Niven's A Mote In God's Eye
 * Interestingly, in notes published elsewhere the authors say that their use of titles like Count, Emperor, etc. were intended as translations of the far-future titles, which would probably be more like Commissar-General, or President. But since the system worked like a feudal aristocracy, they went with traditional names to preserve the feel.
 * Dune is basically nobles feuding IN SPACE. True to the trope, they do have some advanced technology, such as starships and personal shields, but they don't have so much as a computer, and they tend towards knife fighting. All perfectly justified in the backstory - to wit, the Butlerian Jihad, an immense crusade against 'thinking machines' that, among other things, placed House Corrino (Padishah Emperors for the next several thousand years) in power -, naturally. Imagine a mix between the Holy Roman Empire and the Ottoman Empire, complete with assorted duchies, baronies, and counties in space, and that's Dune.
 * The prequel novels also show that feudalism has been around even before the Corrino Imperium, with the League of Nobles, and the Old Imperium before that. No one ever bring up the idea of an elected government.
 * There does not seem to be an explanation why almost no one uses anything longer than a dagger. The Swordmasters of Ginaz appear to be the only ones.
 * Probably due to most of the action we are explicitly shown being close quarters combat between nobles on the run or the Fremen, who by tradition use crysknifes. Another issue is the nature of swords and other bladed weapons - in Dune, shields prevent most of the slashing or blunt force action inherent in how blades are normally used in reality. The slow piercing movement of a dagger counters the shield, but predicates a different fighting style based on slower thrusts. Paul mentions this in his internal dialogue during his fight with Janis, when the other Fremen think he is just moving slowly to toy with him.
 * This is justified by how shields react to ranged weaponry. Kinetic weapons cannot be slowed down like a sword or knife and energy weapons create a massive nuclear explosion, therefore to prevent mutually assured destruction, only knife fighting functions. A technological justification for anachronism.
 * Grenades would still work, though, if you can roll them slowly enough to get inside the shield before detonating. This is actually mentioned when Tio Holtzman first tests the shield on himself by giving a Zenshiite slave weapons to use against the shield. When the slave throws a grenade, he does it with such low force that Norma Cenva fears that it will pierce the shield before exploding. Never mentioned again. Some novels by Herbert's son also have suicide bombers of sorts who wipe out whole regiments by deliberately using Frickin' Laser Beams on shields.
 * The Galactic Empire in Isaac Asimov's Foundation trilogy. This is particularly clear after the breakdown of the empire begins. It is implied, however, that the Empire was a constitutional monarchy, with powers resembling Great Britain in the late 18th century (i.e. the ministers run most of the business of state, but if the monarch wants something done, it gets done.) Although the Emperor's power was gradually removed, by Forward the Foundation, in the later sections, he couldn't really do anything.
 * This wasn't so much because the empire was becoming democratic, as because the court and ministers were becoming so corrupt that nothing the Emperor said had any effect on the facts on the ground after it had been filtered through layers of government officials, each with their own take on what really needed to be done. It's a common problem in empires with a large bureaucracy- the emperor vanishes into the royal palace and for all practical purposes it's the bureaucrats who really run the system.
 * Also in Foundation, the Four Kingdoms that broke away from the Galactic Empire at the start of its fall were feudal. One of them attempting to take over and "impose its own peasant-aristocracy system" on the Foundation was the conflict of that time period, until the Foundation became an Expy of.
 * The prince-regent of Anacreon specifically despised the Foundation for being ruled by a lowly commoner instead of a rightful nobleman, completely ignoring the fact that Terminus was settled by scientists without any noble blood.
 * Katherine Kurtz's The Legacy of Lehr
 * Elizabeth Moon's Hunting Party—although the author was apparently unable to suspend her own disbelief, as the sequel reveals that the feudalism is mostly societal set-dressing over democratic underpinnings, and deconstructs, sometimes unpleasantly, several of the tropes that were used straight in book one.
 * Poul Anderson's Technic History included a Terran Empire. (Deliberately established on feudal-service lines by the "Founder" Manuel Argos the Great, before it went decadent.)
 * There are other cultures that have similar constructs. The Ythrians are tribalistic rather then feudal: that is they do not have one noble as a hereditary ruler of a region(or even a ceremonial one) and pledged by an elaborate web of oaths upward and downward with a great sea of commoners at the bottom. Rather each Ythrian seems plugged into the system by membership in a community which in turn is part of a confederation. Dennitza(a border world of the Terran Empire) is like Serbia in some ways, having Slavic Noble titles and a dominant religion that is an obvious descendant of Eastern Orthodox Christianity. However it is like Britain in having a limited aristocracy and a parliamentary system. Other planets have their own variations.
 * Poul Anderson plays this trope for laughs in The High Crusade, in which a party of Englishmen heading for the Crusades is hijacked by aliens and winds up establishing an empire because the aliens have forgotten how to do combat on land.
 * This is reworked by David Weber in The Excalibur Alternative, which is a sequel to David Drake's Ranks of Bronze.
 * Simon R Green's Deathstalker series is a fairly dystopian version of this trope, and unlike many actually does deal with the difficulty of setting up a working system of democracy, although not in any great detail. Given that it was almost a gleeful self-parody of the whole space-opera genre, this is not particularly surprising...
 * In Poul Anderson's Corridors Of Time, the hero realizes that the futuristic society that recruited him to fight a Dystopia is rather Dystopian itself when he is dropped in it and learns that the queen has high tech medical treatment while the poor woman he meets looks ancient at forty because of her lack of it.
 * M.K. Wren's The Phoenix Legacy, which is a more literal version of a Feudal Future than most: a thousand years after the Pandemic and World War III nearly wiped out world civilization, Earth and its colonies are ruled by noble houses, giving formal and limited obedience to a central government based in what is today Australia. Most of humanity are Bonds (serfs), kept illiterate and oppressed to a greater or lesser degree depending on who owns them. The Fesh are educated professionals (e.g. university scholars, technicians), while the Elite are the aristocrats who control the government. For the past few hundred years, it has been effectively impossible to change from one caste to a higher. The civilization is teetering on the edge of another Dark Age as the story opens.
 * In the Mankeen Revolt, a relatively recent historical memory, Lionar Mankeen attempted to liberate the Bonds by force. The attempt failed miserably and set back social progress a long way because the implementation was not well thought out; the Bonds were not only illiterate, but unused to handling money and working for wages, and Mankeen hadn't made preparations to alleviate those problems.
 * The Society of the Phoenix was working to evolve the civilization into a true democratic republic, although acknowledging there were possible advantages to a constitutional monarchy. It wasn't going to be Easy Evangelism, however; one Phoenix scholar estimated it'd take at least five and perhaps seven more generations before they achieved their goal—and this was after already working on it for fifty years.
 * The Praxis (Dread Empires Fall) has The Peers, Lords and Ladies born to a higher station.
 * Lampshaded in an unidentified Space Opera story. Yes, the Earth of the 35th century (or whatever time it was) has a royal family, but it is purely ceremonial and came into being as the dual result of deregulation of royal succession laws and the members of the few remaining royal families going to the same types of parties, until eventually all the royal families had basically become indistinguishable from one another. Since by this time Earth had ceased to have countries or anything, the idea of their being a British/Japanese/Belgian/Monacoian/Dutch/whatever royal family anymore was dumb anyway so it was just decided that there would be a ceremonial "King/Queen of Earth" instead.
 * Both averted and played straight by H. Beam Piper. Piper's Terro-Human Future History ended with a series of galactic Empires. This was justified: the universe was too big to hold a vote for general leader. Not only counting a vote of trillions, but also transporting the vote took far too long. The aversion is in the planetary governments: Piper's Empire allowed each planet to be self-governing, under a general Imperial constitution that controlled how the planets interacted with each other. This meant that any number of types of governments existed from planet to planet, from enlightened democracies to totalitarian nightmares. The capital planet of the Empire itself, Odin, was actually run as a constitutional monarchy, with a strong parliament to balance out the Emperor.
 * Isaac Asimov's Stars Like Dust takes place in star sector written to resemble feudal Russia under the Mongols' rule.

Live Action TV

 * Stargate SG-1 is set in the present, but the Goa'uld System Lords definitely operated under a feudal system. The main difference being that, due to their nigh-immortality, it was less about lines than about individuals, and holdings would usually pass from father to son by conquest.
 * Star Trek's Klingon Empire has a very feudal feel to it, being organized into noble houses and the like. The Empire has technically always had an imperial throne, but for almost all of its history this was vacant, following the departure of the first emperor, Kahless the Unforgettable. Real power resided with the Chancellor of the High Council. Towards the end of Star Trek: The Next Generation a clone of Kahless was installed as emperor in a ceremonial role.
 * The Centauri Republic in Babylon 5; also the Minbari, in a different way.
 * In Doctor Who
 * The Tharils' past in Warriors' Gate.
 * in Frontier in Space, the Draconian Empire.
 * The 2005 series mentions the New Roman Empire sometime around the year 12,000 (in the 51st century humantity has already spread across half the galaxy) and what should be The Fourth Great and Bountiful Human Empire around the year 200,000 which is supposed to span "a million planets, a million species". It's not specified how these are governed, but the word "empire" does imply hereditary rulers.
 * The Systems Commonwealth of Andromeda was originally the Vedran Empire, but they transitioned to a constitutional monarchy thousands of years before contact with humanity. During the Long Night several feudal and semi-feudal governments arose, most notably some of the larger Nietzschean Prides such as the Drago-Kazov and Sabra-Jaguar, who lord over enslaved populations of "kludges" and sometimes even use titles.

Tabletop Games

 * Warhammer 40,000 has the Imperium of Man, a justified use of a feudal structure on an interstellar scale-given the sheer unwieldy size of the Imperium and the unreliable nature of faster-than-light communications. The central authorities of the Imperium, the Lords of Terra and the Administratum, serves as the feudal lord and appoints one governor for each planet. That governor has three duties: Pay your tithes to the upkeep of the Imperium, turn over any psykers to the black ships, and keep your world from rebelling. As long as those three tenets are upheld, the central authority cares little for how the world is run on a day-to-day basis. Thus, one can find practically any sort of government on imperial planets, from medieval feudalism or military dictatorships to modern-day democracies. The only thing they all have in common is a de jure governor, to be held responsible by the Administratum should the planet lapse in any of its three duties.
 * Along with these three basic duties there were also upholding the Cultus Imperialis, submitting to the authority and supervision of Adeptus Arbites in the matter of the (admittedly few) Imperial Laws and, as a duty to any Imperial citizen, following every whim of the Inquisition.
 * Space Marine Chapters double in as Feudal masters and Knightly Orders. They are semi-independent yet owe their loyalty to the Imperium, and maintain their own upkeep using (usually) a Star System.
 * The Ultramarines are particularly notable in that their dominion encompasses multiple star systems.
 * Everyone not part of the Clans in BattleTech. Feudal-like systems were initially adopted due to simple practicality: there was FTL travel on the scale of weeks, but no FTL communication faster than a courier. So a ruler of an interstellar empire needed someone on-hand he could trust to take care of the day-to-day management. Even after the advent of FTL communcations, they maintain a feudal society. When the Inner Sphere joined together in the Star League, the head of the Terran Hegemony became First Lord, but his power was semi-limited by the heads of the other member nations in the Star League. Once the Star League was destroyed, it basically became 5 separate feudal nations at war with each other.
 * Each of the 5 nations of the Inner Sphere has its own take on their feudal system:
 * The Federated Suns is a pretty straight-up Medieval European feudal system, with nobles having almost total power over what happens within their fiefdoms, override only by higher nobles in the hierarchy. It's a fairly free society however, with citizens have freedom of speech and the right to protest the actions of nobles. The nobles who try to suppress these rights are usually striped of power or executed.
 * The Draconis Combine is basically feudal Japan, though with less direct conflict among nobles; high-ranking military leaders can often have greater power than planetary lords.
 * The Free Worlds League is something of a democracy (it is also the nation with the most civil strife), but each of the member states and worlds in the League is a feudal society. Their ruler has the title "Captain-General", and his family has the right of first refusal of that tile. The Captain-General was initially just the highest military rank, until the League Parliament voted to give the Captain-General special powers "for the duration of the conflict." Naturally, the conflict has not been deemed to be ended, even after 300 years.
 * The Capellan Confederation is a fairly traditional feudal system, though it has quasi-Chinese and Russian trappings. It also has the notion of having to earn ones citizenship.
 * The Lyran Commonwealth is an odd form of feudalism. Feudal lords are more like chief executors in the overall governmental power structure, rather than absolute rulers. And one can gain nobility by becoming the head of a large corporation. This doesn't confer any de-facto powers on them, but it does give them access that might otherwise not have been granted. The nobility and the military even merged to a degree during peacetime. These "Social Generals" seriously screwed up the Commonwealth military once peace was over, infusing it with a lot of politicking that has lead to the richest nation having the least effective military.
 * The Clans have something of a merit-based feudal system, at least among the ruling warrior caste. You have to actually earn your last name, called a "bloodname", in a Trial of Bloodright. These battles often are to the death. Once you have a bloodname, you get to have a vote on clan-wide business.
 * Fading Suns role-playing game is set in a Dune-esque interstellar feudal empire, millennium after the fall of the Republic. The peasants are forcefully (nobles) and brainwashingly (the Church) restricted to medieval-level technology, while the upper echelons of the society are allowed to enjoy high-tech to the fullest.
 * The Third Imperium of Traveller is one of the earliest RPG examples. Individual planets are more or less autonomous and can have practically any form of government, but the space between them is the domain of the local nobility. As Jump drive takes a week regardless of distance traveled and most drives can only jump a couple parsecs at a time a hierarchy of nobles is one of the few governments that can function across such a vast region of space.
 * The system of nobility is complex. For instance a noble's estate is not the same as his office. For instance the duke of a given subsector does not hold that subsector as part of a family possession. He holds it as a sort of satrapy. At the same time he will likely have several different estates that he is a direct Feudal Overlord over. How the Third Imperium assures loyalty in it's nobles is not made clear (though it's implied the Imperial Navy and Marines have something to do with it).
 * The Imperial Naval officers are themselves drawn from the nobility making that a tricky thing to lean on and in any case while all states need muscle a state that only has force to back it is a fragile one. More to the point the Imperium provides multiple avenues for ambition in a complex society and is able to give nobles estates so far separated that their power is best assured by supporting it. Those things are not precisely stated in canon however they are reasonable conclusions based on description.

Video Games

 * The Elites/Sangheili from the Haloverse have a society set up in this manner. They even have their own keeps to rule over the surrounding countryside.
 * The leaders appear to be elected by the local council.
 * The accepted way to express disagreement or disapproval with a leader is to assassinate him. However, if it fails, then the leader has a right to kill the councilman who has sent assassins, usually for cowardice. A proper Sangheili would do the job himself. If the leader kills the councilman for cowardice, then he may also have his entire family slaughtered or exiled, depending on his mood.
 * The Amarr Empire in EVE Online, complete with a theocratic government and widespread use of slavery.
 * Imperium Nova's whole schtick. Each player controls a feudal house with operations spanning several planets in a galactic empire theoretically under the rule of an imperial house. Though planetary governorships are elected.
 * The emperor of the Capricorn server has recently allowed houses to claim their homeworlds as Satrapies.
 * In Mass Effect, the salarian society is this, according to the Codex. Though they are matrilineal rather than patrilineal like most other examples due to their haploid-diploid sex determination (males hatch from unfertilized eggs).
 * One of the government options in the Master of Orion series.
 * It appears that three of the four Houses in Freelancer have (at least, partly) a feudal system. Bretonia resurrects the British constitutional monarchy. Kusari has an Emperor and local lords. Even Rheinland goes back to the old days of unified Prussia and has its own aristocracy. Liberty appears to be the only one with a purely democratic government.
 * It is unclear if the nobility of Rheinland has any actual power by virtue of their titles anymore, but Rheinland at the very least was this trope, before a disastrous conflict led to a revolution that toppled the Emperor (and established a republic that may or may not have been about as democratic as Liberty, if more unstable, before ).
 * Imperial space in Frontier Elite games.
 * Vega Strike human faction Highborn. They seem to think of themselves as Knight in Shining Armor better than anyone including superhumans. Highborn are noticeably decadent, but there's enough of high-end jousting forces to back up their claims.

Web Comics

 * The interstellar Nemesite Empire in The Inexplicable Adventures of Bob has been shown to have an emperor, a princess, and solar system viceroys. As well as trials by combat.

Web Original

 * In the history of Orion's Arm a number of Great Houses emerged as the First Federation declined. But by the 106th century A.T. most have been supplanted by the Sephirotic Empires of the Archailects.

Western Animation

 * In Xyber 9: New Dawn, there are kingdoms, empires and lots of peasants, and yet there's also hoverbikes, Airborne Aircraft Carriers, and various forms of energy weapons.