This pairing is firmly rooted in medieval stories and symbology. In European Christianity, serpents and dragons represented satanic powers, a connection ultimately derived from the serpent of Eden, and Satan himself was often depicted as a draconic beast (explictly in the Book of Revelation). Knights were instead associated with a marriage of piousness with the warrior ideal, serving as the archetypal champions of Heaven and righteousness on Earth. The image of a knight slaying a hideous dragon was thus a popular metaphor for good's triumph over evil.
In modern works, this allegorical angle is largely forgotten and the association of knights with God and dragons with Hell is no longer very common, even when these are still respectively portrayed as good or evil. However, as this motif was extremely widespread in European history, it's still common and well-known despite outliving the cultural context that gave it birth.
This trope is particularly common in fairytales and fairytale-inspired settings, but also shows up in other fantasy worlds. It's typically played very straight in traditional fairytales, but is usually played with in modern works. One variant has the moral sides reversed, with a sympathetic dragon and a villainous knight. The extent and nature of this rivalry also changes; it may be a sporadic series of conflicts with little overarching structure, an organized feud, or even a form of Fantastic Racism. Which side holds an advantage is also prone to varying; medieval knights always killed their dragons, but their modern counterparts, no longer favored by cosmic power, find the odds far more in the dragon's favor unless the knight gets clever about things.
"Knight" and "dragon" use fairly specific meanings in this context, knights being the medieval European kind in plate armor and dragons being the Western fire-breathing type.
See also Dragons Prefer Princesses, which this trope is often paired with — the setup of a knight facing a dragon to rescue a kidnapped princess is a fairytale classic. Contrast Dragon Knight, when either the knight is themed around dragons or the dragon is the knight. Also contrast the Dragon Rider, who rides and may fight alongside a dragon instead of against it. If a knight is successful at defeating his foe, he may become The Dragonslayer.
- Yu-Gi-Oh! GX: The main protagonist Jaden uses a deck of Warrior-type monsters called the Elemental Heroes while two of his rivals use dragons; Chazz uses the Armed Dragon as one of the archetypes in his deck while Zhane uses Cyber Dragons, Machine-type monsters with dragon appearances. In the manga, Chazz uses a Dragon-type focused deck.
- Yu-Gi-Oh!: Bonds Beyond Time: While Yugi relies primarily on his spellcasters, Yusei and Jaden use mostly warrior monsters. The main villain Paradox relies on corrupted versions of well known dragon cards. Yusei and Jaden even have a fusion of Elemental Hero Neos and Junk Gardna called Elemental Hero Neos Knight.
- Disney Ducks Comic Universe: In a story where one of Gyro Gearloose's inventions allows creatures and characters from imagination to enter reality, a fairytale dragon is amongst the newly real beasts roaming around Duckburg. He makes it very clear that he does not like knights errant, which he considers to be dragons' worst enemies, and pointedly questions Huwey, Dewey and Louie as to whether any of them plans to become a knight errant when he grows up.
- JLA: A League of One: The opening prologue features Drakul up against an army of European knights, who eventually force the dragon to flee into hiding in the Swiss mountains.
- My Little Pony: Friendship Is Magic (IDW): In From the Shadows, when the main characters are trapped in short time loops based on museum exhibits, Fluttershy and Spike find themselves in a battle between knights and a dragon. The knights are hostile enough towards dragons to treat the presence of the baby dragon Spike as an enemy intrusion, while the dragon is very vocal about the enmity between his kind and theirs, and that he's attacking in retribution for their attacking dragons in the past. Fluttershy is able to defuse the situation by pointing out that this animosity is just perpetuating a Cycle of Revenge where each group attacks the other in retribution for the other attacking them.
Fluttershy: Excuse me, mister dragon, sir? But why are you tormenting these ponies?
Dragon: Are you kidding? Because they're knights! They try to slay dragons!
- Iron Man: The relationship between Fin Fang Foom and Iron Man is nothing short of a sci-fi adaptation of the Knight & Dragon trope.
- Calvin and Hobbes: In one of Calvin's many fantasies, he imagines himself as a fierce, fire-breathing dragon that utterly destroys a knight foolish enough to challenge him in his lair.
The knight is fried to a crunchy crisp... his armor fused into a solid piece! The dragon circles overhead, daring other fools to come after him!
- The Far Side: A couple of strips play off of the enmity of knights and dragons, skewed in the dragons' favor. One features a dragon handling the scalding hot armor of a freshly roasted knight and calling for his wife to hurry up with the hot pads; another has an irritated dragoness scolding her husband for eating in bed and leaving leftovers (i.e., knights' armor) all over the sheets.
- The Wizard of Id adopts a dragon in the 2019 strips, and keeps it as a pet. In many ways the dragon behaves like a dog, but turns fiery at the sight of gleaming steel. The knight Sir Rodney rarely removes his chainmail outfit, so he routinely incurs a toasting from the Wizard's dragon.
- Child of the Storm: The Of Dungeons and Dragons arc in the sequel culminates in this, with Harry doing the bulk of the fighting against the Elder Wyrm (which had been dormant until disturbed by the First Task of the Triwizard Tournament, before playing up the Smaug influence and tormenting the other Champions), being sardonically referred to as "the Knight In Shining Armour" by Wisdom. Funnily enough, it's also quite literal, as Harry has at this point been knighted, thanks to the Battle of London, and is a member of the Order of the Garter.
- In Hercules, Hercules is more of a hero rather than a knight, but he is of noble birth and wields a sword. In order to kill Hercules, Hades sends the Hydra, depicted here as a giant dragon-like creature. While the first battle was more of the traditional dragon vs knight, it goes crazy after Hercules cuts the Hydra's heads off to the point of the monster having dozens of heads. Hercules successfully kills the multi-headed monster after a rockslide.
- Pleasant Goat and Big Big Wolf: In the fourth movie, Mission Incredible: Adventures on the Dragon's Trail, the goats and wolves don brightly-colored knight armor as they go on a quest to stop the evil dragons from causing turmoil in the dragon world and, by extension, in the Green Green Grassland.
- The Reluctant Dragon has this conceit as part of its central plot. The titular dragon and a Knight Errant know they're supposed to be mortal enemies but are so similar in interests that neither has any real desire to fight the other (especially since the dragon knows how such fights usually end). Ultimately the two pull off a theatrical fake fight that appeases the villagers and allows the dragon to become an accepted member of the community.
- Ritterschlag is a short film about an older dragon teaching a younger one how to properly defend against an endless stream of incoming knights, which are for the most part beaten about like hapless ragdolls.
- Shrek: Deconstructed to heck and back as per the norm of the series. Shrek and Donkey are tasked with saving Fiona by Farquad in a deal for the former to get his swamp back from the fairytale creatures Farquad dumped into it. They reach the castle but naturally Shrek doesn't bother going by tradition despite donning a knight helmet, instead going straight for Fiona and just opting to run for it when the dragon catches on. When Fiona protests about doing it the usual way, Shrek points out that others who tried that ended up as scorched hunks of metal and bones. The dragon turns out to be an asset later on when Donkey finds out she's female and ends up charming her.
- In Sleeping Beauty, Prince Phillip is never actually stated to be a knight, but he wields a Knightly Sword and Shield provided by the three fairies. To stop him from rescuing Princess Aurora, the evil Maleficent transforms herself into a fire-breathing dragon. Phillip successfully kills Maleficent with the fairies' help.
- Dragonheart: Zigzagged. Sir Bowen swears vengeance on all dragons after Draco saves his master Prince Einon's life by gifting him half his heart, only for now-King Einon to turn into a tyrant. Bowen spends the next several years as a professional dragon hunter, but after stalemating against Draco, now the last dragon, partners with Draco to scam villages out of dragon bounties and in the third act, to lead a peasant uprising against Einon. Ultimately he's forced to slay Draco in order to kill Einon.
- Enchanted: The finale introduces a dragon our heroes have to fight with a prince's magical blade in a play on the example of this trope in Sleeping Beauty. The twist is that the dragon-slayer here is not the brave knight who rescued the princess, but the princess herself, slaying the dragon with his sword.
- Enchanted Forest Chronicles: This, like all major fairytale tropes, is explicitly encoded in in-universe custom and occasionally lampshaded. Slaying a dragon, preferably one who kidnapped a princess or is otherwise menacing a kingdom, is a common and well-respected rite of passage among knights and princes. The dragon is expected to fall eventually, but also to take a fair number of challengers with it — some knights won't even think of challenging a dragon who hasn't itself slain a respectable number of knightly foes. Cimorene gets to read up on a history book which, in a setting where knights register in her life as annoyances and she lives with dragons by choice, details a history of dragons that includes the crimes typically associated with them, "defeating knights and princes" and, it registers as the exception, "occasionally being defeated by them".
- The Faerie Queene: The penultimate book is dedicated to the epic, two-day long battle between the Saint George, armed with sword, shield, and lance, and the dragon, armed with its whole body. Since George is a Knight in Shining Armor representing holiness, having his Final Battle be with a beast biblically associated with the Devil is quite fitting.
- Farmer Giles of Ham: The work parodies the convention of dragon-slaying knights through the eponymous farmer, who gets in possession of a legendary dragon-slaying sword and needs to pose as a knight to slay the dragon that menaces the region. The actual knights are portrayed as completely useless.
- The Flight of Dragons by Peter Dickinson says dragons were extinct long before knights in armour existed, but that it could be a race memory of stone age tribes seeing the local dragon get killed by a wanderer from a region that had discovered how to smelt metal, hence the metal being seen as an important part of the story.
- Guards! Guards!: Invoked: when the Dragon sees the (supposed) heroic prince on a white horse brandishing a shiny sword and wearing a shiny armor as expected, the narration points out that the sight causes her to recognize the figure as something akin of a "natural predator".
- The Non-Existant Knight: Dragon-hunting is mentioned as a pastime for the paladins of Charlemagne, with one of them boasting about one of his deed of Dragon-slaying... only for the protagonist to kindly point out that it happened during a season in which Dragons moult their skin and become easier to kill, much to the other knight's annoyance.
- A Song of Ice and Fire: While knights are just heavily armed warriors and no more likely than anyone else to survive against a dragon, which are essentially living weapons of mass destruction, there are several legends of dragonslaying knights. Serwyn of the Mirror Shield slew the dragon Urrax by approaching it while staying behind his reflective shield, keeping the dragon transfixed with his own reflection until he got close enough to spear it through the eye. Sir Galladon of Morne slew a dragon with his enchanted sword. Davos of the Reach, who is described as a knight despite having lived centuries before the origin of Westeros' knightly tradition, is better known as Davos the Dragonslayer.
- According to The World of Poo, this is why dragon poo sometimes appears to come in tins.
- Game of Thrones: There are plenty of knights in Westeros, but initially, dragons have been extinct for decades. When Daenerys' newly hatched dragons grow to full size, she trains them for warfare. We finally see an actual "Knight in Shining Armor vs Dragon" scenario in season 7's "The Spoils of War", when Daenerys uses her biggest dragon to decimate an enemy army. When it's wounded and she has to jump off, Jaime smells an opportunity and charges them with his mount. As with many fantasy tropes, it's deconstructed: Jaime is really aiming for Daenerys, not Drogon, but it's a blatantly suicidal move to charge a giant firebreathing reptile armed only with a lance. If not for Bronn's Diving Save, Jaime would have been incinerated before he even got close. Jaime himself isn't a particularly reputable character either, being an incestuous kingslayer with his fair share of atrocities.
- Once Upon a Time:
- In "The Shepherd", David's first task as a prince is to lead a group of knights in a battle against a dragon. Through his cleverness and care for his men, David fells the dragon, is accepted by his father as a rightful heir, and is engaged to a beautiful princess of a wealthy kingdom.
- The first season finale also plays off the classic knight vs dragon trope by pitting Prince Charming against a dragon on his quest to free Snow White from the sleeping curse. His daughter takes up his sword and has to fight the same dragon in the present day.
- Reading Rainbow: The original opening theme had a part where a kid read a story about a knight fighting a dragon. And using its fiery breath to toast a marshmallow.
- Saint George is one of the most archetypal examples of this. In the original myth, George of Lydda is a wandering Cappadocian soldier who comes across a city being held under siege by a dragon that demands periodic sacrifices of people. George slays it just before it devours the city's princess, whose turn it was to be fed to the beast, on the condition that the city convert to Christianity. In medieval and later retellings and depictions of the story, however, George is invariably depicted as a high medieval armored knight, typically slaying the dragon from horseback.
- St. Michael, the archangel who cast Satan out of Heaven, is often depicted as a warrior or knight fighting a dragon — in this case, the dragon is literally Satan, as the Book of Revelation depicts, along with later art (probably most famous of these are by William Blake, in his series of Great Red Dragon paintings).
- Dungeons & Dragons:
- Dragonlance prominently features heroic knights wielding the titular weapons against evil dragons. Played with, as the proper way to use a Dragonlance is when flying on the back of a dragon.
- The 3.5 Edition Prestige Classes Platinum Knight and Vassal of Bahamut are all about this trope. Both are knights in a religious order whose primary duty is to track down and slay evil dragons who threaten the helpless.
- Warhammer: Bretonnia is heavily based on Arthurian myth and chivalric romance, and the theme of the heroic knight laying low a fearsome monster is consequently often used. Naturally, the archetypal foe of its wandering knights, and the most coveted by ones seeking to earn a name, is the dragon.
- Gilles le Breton, Bretonnia's first king, rose to fame when he fought and killed the legendary dragon Smearghus, who had been ravaging his land's countryside.
- His descendant, Duke Bohemond Beastslayer, himself slew a dragon in his younger years and crafted his mace's shaft from its thighbone.
- Jasperre le Beau, also called Jasperre the Dragonslayer, is particularly skilled at this; he killed the dragon Malgrimace while rescuing the king's daughter, and in his wanderings since then has killed many other dragons in addition to other monsters.
- Warhammer 40,000:
- The Adeptus Astartes are pretty much knights IN SPACE, and the Salamanders (one chapter of the Astartes) live on the planet of Nocturne. The planet is inhabited by massive fire-breathing reptiles called Fire Drakes, which the Salamanders often go on journeys to slay. The primarch Vulkan and the God-Emperor himself have both slayed Fire Drakes together during the Great Crusade.
- Back in his youth, the God-Emperor of Mankind personally battled Mag'ladroth, a Draconic Abomination also known as the Void Dragon, weakening it to the point that it became a Sealed Evil in a Can underneath the surface of Mars, which story became the legend of Saint George. Unfortunately, it's now more-or-less worshiped by the Adeptus Mechanicus as the Omnissiah.
- Cookie Run: Knight Cookie is a pretty standard Knight in Shining Armor whose greatest achievement is cutting of the tip of Pitaya Dragon Cookie's Tail. In his Icewind Cavalier costume, he proclaims he is the only cookie strong enough to defeat the dragon, and the he'll cut off more than just the tail. However, this rivalry seems to be pretty one-sided, as Pitaya Dragon seems to have barely noticed their missing tail, and in Kingdom they outright state that they completely forgot about it.
- Dark Souls: the opening of the game has Lord Gwyn and his Silver Knights fighting a war to wipe out the Archdragons and reclaim the land of Lordran as their own. A shining example is the demigod Ornstein, a lance-wielding knight who rightfully carries the title of Dragonslayer for his ability to hunt and slay Dragons (you can even find a room with the walls filled with dragon trophies).
- Divinity II: The Dragon Knight Saga: The protagonist is a rookie member of the chivalric order of Dragon Slayers that is waging a religiously-motivated war against the dragons, whom they blame for the death of the Divine. The knights appear to have won the war by exterminating the dragons, but the latter then suddenly reemerge, and the protagonist, who is sent to deal with it, is instead converted to the dragons' cause and becomes a Dragon Knight instead.
- Dofus: In the backstory, the courageous Iop knight Rykke Errel encountered the mighty dragon Bolgrot, apparently to fight him. Against all odds, the two actually became friends for a long time... until one day Rykke married a beautiful sorceress named Helsefine and introduced her to Bolgrot who, unexplicably, went into a rage and killed her. Furious, Rykke fought Bolgrot for real after a titanic battle which ended with a mutual kill and the recovery of the Six Primordial Dofus from the belly of Bolgrot.
- Dragon's Lair: Pretty much the central premise of the game. You play as a knight named Dirk braving the lair of Singe the dragon to rescue the damsel, ultimately ending in a one on one battle against the dragon.
- Dragon's Wake: The player is a young dragon, while the villain is a Black Knight that has already killed several dragons and intends to add the player to that list.
- Fire Emblem has man vs. dragon as a central storyline for much of the series, usually following The Chosen One who can wield a historic blade that can destroy an evil dragon.
- Gems of War: Several Knight troops have traits or sometimes even spells that deal more damage to Dragons.
- King's Bounty: Knights/Paladins deal bonus damage to Dragons.
- Knights And Dragons: You play as a knight, upgrading your armor and weapons in order to fight enemy dragons.
- The Legend of Kyrandia: No knights are seen in Kyrandia despite Brandywine the dragon apparently being expected to eat them. She refuses to, complaining that they're "all sweat and muscle, and so hard to peel".
- Overwatch: The supplementary comic "Dragon Slayer" pits Reinhardt, a character themed heavily around medieval-style knights and chivalry, against a group of gangsters called the Dragons.
- Zacian and Zamacenta from Pokémon Sword and Shield are armored wolves who protect Galar's monarchy and its subjects with a magical sword and shield against the evil power of the immortal dragon, Eternatus. Since Galar is Pokémon's equivalent to Britain, it's pretty clear that Game Freak looked to some of Britain's most famous legends, like those of King Arthur and Saint George, for inspiration.
- Sonic and the Black Knight: Fittingly, the first and penultimate boss is a winged dragon, each protecting a magical sword Sonic needs to complete his quest of knighthood and save Camelot from dark magic.
- Thanatos on the ZX Spectrum: You play as the dragon, fighting various enemies. When the dragon runs out of flame, it refuels by eating a witch. Each witch is always guarded by a knight on horseback, whom you need to kill before you can eat the witch.
- Tower Unite: In Little Crusaders, a group of knights have to take down a dragon by pushing a button on his back.
- Arthur, King of Time and Space: In the baseline arc, Lancelot and other knights are occasionally seen dragon-slaying. In the space arc, the Dragons are a humanoid, space-faring race who the Excalibur crew sometimes come into conflict with.
- Girl Genius: When the battle between Franz, the biomechanical dragon construct who guards Mechanicsburg, and another dragon is interrupted by a group of giant robots sent by the Knights of Jove, Franz asks the other dragon if these guys are on his side. The latter is apparently quite insulted by the implication that he would associate with knights.
Franz: Ah— some of your... friends?
Red dragon: Don't be insulting. They're knights!
- El Goonish Shive: The Writer's Block fights a dragon with a sword at one point and ends up saving a princess.
- Critical Role: The Platinum Knights are an order of paladins who swear oaths to protect the holy city of Vasselheim and kill any evil dragon they find in honor of their patron, Bahamut, lord of all good dragons. Their most notable member is Lady Kima, a little hafling woman whose platinum plate armor and her magical two-handed sword allow her to help the heroes more than anyone else in their battles against the ancient dragons bent on destroying human civilization.
- Blazing Dragons inverts this trope's traditional morality — the protagonists are a group of heroic dragon knights, and their arch-enemies consist of a group of evil human knights.
- The Grim Adventures of Billy & Mandy: In "Dumb-Dumbs and Dragons", Billy goes back in time to the Middle Ages to learn how to be brave, and becomes an apprentice to a knight who tells him that, as a rite of passage, all knights must slay a dragon.
- Hercules: The Animated Series: Hercules is more of a hero rather than a knight, but he is of noble birth and sometimes wields a sword. In "Hercules and the Living Legend", Phil teaches Hercules in fighting dragons only for the hero-in-training to fight Memnon, who is half-dragon and half-man.
- Phineas and Ferb: The legend of the Black Knight of Worcestershire involves the knight going off to fight a dragon.
- Sofia the First: "The Tale of the Noble Knight" focuses on the land of Brazendell, where the native dragons have suddenly started setting fire to buildings. While investigating this, Sofia meets Sir Oliver, an arrogant knight who seeks to find a magical artifact and use it to drive off the dragons. It is eventually revealed that Sir Oliver had intentionally provoked the dragons into breathing fire so he could drive them off and look like a hero. Sir Jaxon, a knight who is friends with the dragons, helps Sofia to expose the truth.
- Wander over Yonder: "The Hero" has Wander and Sylvia help a knight try to rescue a princess from a supposedly evil dragon, only to find out three things —
- The "knight" is a whiny, pompous jerk who views himself as a hero when he's really a Dirty Coward.
- It turns out that the "evil" dragon is actually pretty friendly.
- Tying into the above example, it's revealed that the dragon never kidnapped the princess—in fact, the dragon and the princess are a couple (and are genuinely in love at that). In fact, the trio had arrived just as the dragon and the princess were about to get married (the dragon's initial demeanor was apparently was apparently nothing more than the result of prewedding jitters). The knight just has a hard time accepting the reality of it.