This is a classic FairyTale written by Creator/HansChristianAndersen, about a mermaid who seeks to become human.

In this tale, mermaids live for centuries but have no afterlife. The youngest mermaid of the royal family is allowed to go up to the surface once she turns 15, and for several years in a row she longingly drinks in the tales her older sisters tell her of what it is like up there. When her time comes, she rescues a human prince from a storm and falls in love with him.

She then makes a deal with the Sea Witch to become human, but at heavy cost. The Sea Witch grants her legs and inhuman grace, but it will feel painful to walk, as if she is always stepping on swords. The mermaid also gives her tongue as payment. If she can make the Prince fall in love with her and marry her, she can gain a share in his soul and be human all her life, but if he marries another, she will die at the next dawn after his wedding day.

The prince she loves finds her and, charmed by her grace, takes her in and makes her a sort of pet.

Then he is betrothed, and his intended bride turns out to be the temple maiden he fell in love with at first sight when she found him on the shore after the little mermaid rescued him from drowning. As the mermaid mourns, her sisters appear to her with a LastSecondChance -- she can kill the prince with the enchanted knife they give her and live out her centuries as a mermaid -- or she will die at dawn. Unable to murder the man she loves, the mermaid throws herself into the sea and dissolves into sea foam.

Andersen revised the tale twice, first to change the sad ending to a bittersweet one ([[WordOfGod which he said he intended from the beginning]]), and then to make the ending have more of a moral to it adding that the little mermaid has become a "daughter of the air" and after 300 years of good deeds, can get an immortal soul and go to Heaven.

The story has been adapted several times, from ballets, to musicals, to the the 1989 hit Franchise/DisneyAnimatedCanon film, ''Disney/TheLittleMermaid''. The Disney version changed the ending to a HappilyEverAfter one, and several [[LostInImitation subsequent adaptations]] have followed suit.

It can be read online [[ here]].
!!Provides Examples Of
* AnAesop:
** On the surface, it seems to say "[[LoveMakesYouDumb don't give up your life for love]]", as the Little Mermaid, who could swim around, do as she pleased, and live for 300 years under the sea, gave it all up because she fell in love and ended up dying because the prince loved someone else. However, since the reward for the path the Mermaid has taken is no less than an eternal life in heaven, it turns out that the message is quite the opposite - LoveRedeems, and the classic Christian theme of redemption through ordeal is unmistakable throughout the entire story.
** The latest ending makes the good deeds time adjust depending on whether children are being good or bad, with more time off for good behavior than time added for bad behavior.
* AgonyOfTheFeet: The Little Mermaid always feels like she is walking on blades, while she is human.
* AndIMustScream: You have sold your tongue and you feel like walking on blades every time you set a foot on ground without being able to complain about the pain. ''And the mermaid was said to be a gifted dancer. ''
* AuthorAvatar: The story was written around the time a man Andersen loved romantically was getting married. There are claims that at the time, [[TearJerker Andersen was writing desperate letters that he didn't dare send, saying "I want to tell my love, but I cannot speak."]] Sound familiar?
* BecomeARealBoy: Mermaids live for three hundred years and then dissolve into sea foam, having no afterlife of any kind. The protagonist's ongoing wish, even prior to her falling in love with the prince, is to become a human and acquire an immortal soul though in many adaptations this is completely ignored in favor of emphasizing the love story.
* BittersweetEnding: The mermaid is given a choice to kill the prince and return home or not and turn to sea foam. She chooses the latter. However, after doing about 300 years of good deeds she can gain an immortal soul and go to heaven.
* CessationOfExistence: Mermaids live longer than human but don't have an afterlife.
* CuteMute: The mermaid as a human.
* DarkIsNotEvil: Unlike the villainous Ursula from the Disney movie, the sea witch in the original tale was a neutral character. She had no ulterior motivations, her demand of the price was simply payment, and she gladly helped the mermaid's sisters in saving her, in addition to warning the mermaid of the deal's consequences.
* EveryoneHasStandards: The Little Mermaid's sisters trade their hair for a knife that The Little Mermaid can use to kill the prince and use his blood to return herself to mermaid form. She cannot bring herself to do this (although it does help get her the chance to earn an immortal soul).
* EverythingsBetterWithPrincesses: The Little Mermaid, her sisters, and the girl who helped the prince after the Little Mermaid saves him.
* FashionHurts: The Little Mermaid had oysters attached to her tail by her grandmother to show her great rank.
--> '''Little Mermaid''': "But they hurt me so."
--> '''Grandmother''': "Pride must suffer pain."
* HeroicSacrifice: The mermaid is given the chance to kill the prince so she can continue her life, but she is unable to do so and dies herself in return.
* {{Irony}}: The Little Mermaid saved the prince, but left before he could see her. He actually fell in love with a girl at a nearby temple who helped him, who later turned out to be a princess from a neighboring kingdom.
* IWantMyBelovedToBeHappy: The mermaid chooses to spare the prince and is finally fine that he's happy with another woman.
* LastSecondChance: If she wants her life spared, the mermaid has to kill the prince, or she will turn into foam.
* LikeBrotherAndSister: The prince's feelings towards the mermaid.
* LoveAtFirstSight: The mermaid towards the prince. [[AllLoveIsUnrequited The prince towards another girl.]]
* LoveRedeems: The reason why the mermaid chose to die rather than kill the prince.
* NamelessNarrative: Almost no one is referred to by name, just their titles.
* NoAntagonist: The tale is a tragedy, but doesn't have a real villain.
* OurMermaidsAreDifferent: They can go to the surface when they are old enough, and lack immortal souls. They also live for 300 years.
* OurSoulsAreDifferent: Mermaids lack one, humans have one, and daughters of the air can gain one.
* PerfectlyArrangedMarriage: Although the Little Mermaid accidentally helps that along, the prince and the girl from the temple fall in love when it turns out she's a princess from a neighboring kingdom.
* RescueRomance: Although with tragic consequences.
* SolitarySorceress: The Sea Witch lives by herself in a dangerous part of the ocean. Unlike in the [[Disney/TheLittleMermaid Disney adaptation]], here, she's a TrueNeutral character who tells the mermaid about every negative consequence her spell has.
* TheSoulless: Mermaids have no soul.
* TongueTrauma: The Little Mermaid trades her tongue as part of the deal.
* UnrequitedTragicMaiden: The titular mermaid, who ultimately chooses the prince's happiness over her own life and turns into sea foam. In some versions, she is rewarded for her sacrifice with becoming an air sprite.
* UpdatedRerelease: Twice.
* WantingIsBetterThanHaving: The Little Mermaid wishes to be a human and marry the prince. Because she gave up her mermaid life and became a human not being able to ever speak again and feel pain when she walked and danced and the possibility that she will die, it seems it would have been better for her to keep wanting instead of getting it.