This trope applies whenever a villainous character has romantic and/or sexual feelings for a heroic one.
If this crush takes a turn for the perverse (and most such crushes tend towards this), this can lead to tropes like I Have You Now, My Pretty, Forceful Kiss, Bathe Her and Bring Her to Me, And Now You Must Marry Me, Scarpia Ultimatum, and Go-Go Enslavement where the villain tries to force their desires upon the character, although none of those require a Villainous Crush. Additionally, the villain may become a Stalker with a Crush. If the crush itself is a motivating factor in their Start of Darkness, then it's Love Makes You Evil.
This trope isn't always negative, though. This trope can conversely be a very humanising trait for an Anti-Villain. The heroic character may become a Morality Pet, and can be fairly certain that their villainous admirer will never harm them or allow harm to come to them, barring certain exceptions. They may even step in to protect them from other villains who have fewer compunctions. Taken all the way, it may become Love Redeems.
If the feelings are mutual or an actual relationship develops, then it's Dating Catwoman instead. When this is purely subtextual, see Foe Romance Subtext. The specific variant when the Evil Empress captures the hero to seduce him is Villainesses Want Heroes. Not to be confused with Foe Yay, which are purely audience reactions.
- Steele for Jenna in Balto, but she's into the titular main character.
- Batman: The Killing Joke: Paris Franz has a massive interest in Batgirl.
- Gaston to Belle from Beauty and the Beast, developing from a simple Jerkass Prince Charming Wannabe to a Yandere out to Murder the Hypotenuse and throw her father in the asylum if she won't submit to him.
- Frollo to Esmeralda in The Hunchback of Notre Dame. The Villain Song "Hellfire" is about his conflict over him lusting after her when she's a gypsy and he's a "righteous" man of the church.
- The titular king, actually a painting of the real king, of The King and the Mockingbird falls for the Sheperdess, another painting come to life, and the main conflict of the film revolves around the king trying to marry the Sheperdess while not letting her be with her actual love, the Chimney Sweep.
- The title character towards Roxanne since before the events of the film, as confirmed by the filmmakers' commentary. Neither of them realize until he starts dating her as his alter-ego Bernard and everybody had assumed she and Metroman were an item (turns out they were Just Friends).
- Hal/Titan, who only wanted to be a superhero to get Roxanne's attention. When she rejects him, he turns into a villain.
- Maynott for Lucille in A Monster in Paris. It's obvious he's eager to have her as a Trophy Wife.
- Eris shows an attraction to Sinbad in Sinbad: Legend of the Seven Seas, namely by calling him cute more than once and constantly getting into his personal space.
- In Strange Magic, Roland wants fairy princess Marianne, as it would make him king. She nearly fell for it until he cheated on her on their wedding day. Now, he's still pursuing her despite her aversion to him.
- In Norse Mythology, more than one of the jotuns (frost giants) tried to woo Freya (goddess of love), either by trickery or blackmail. Thyrm was a giant king who stole Thor's hammer, hoping to blackmail Asgard into giving him Freya. (They pretended to agree with this, and Thor went dressed as Freya; Thrym and his court, being nearsighted, stupid, or both, was fooled by the disguise, and was crushed - literally - when Thor got it back). Also, there was giant who disguised himself as a laborer, and offered to build a wall around Asgard in exchange for Freya. (They only agreed to this if he could do so in three seasons, without help; when it looked like he might succeed - he was a giant in disguise, using an enchanted stallion to haul materials - Loki took the form of a mare and seduced the stallion. The guilder got angry, his disguise slipped, and was struck down by Thor.)
- Judge Turpin of Sweeney Todd: The Demon Barber of Fleet Street developed two of these. The first was on Sweeney's wife, Lucy Barker, which ultimately led him to kick off the plot by having Sweeney transported for life, followed by luring her to a masked ball and raping her. The second was on Sweeney and Lucy's daughter Johanna, who he adopted out of remorse for what he did to Lucy but came to desire as more than a daughter as she grew older.
- Mrs. Lovett has one for Sweeney Todd himself, though they're both more Villain Protagonist than heroes.
- Jud for Laurey in Oklahoma!, though how much one considers Jud to be a villain is up for debate.
- Count Gregor for Sophia in Fools.
- Abigail Williams has one on John Proctor in The Crucible.
- J.D. and Veronica of Heathers are actually dating for the majority of the show, and are nearly in Unholy Matrimony territory (Veronica being manipulated into participating in J.D.'s murders rather than doing it of her own free will is what stops it from being a straight example of the trope). After Veronica finally gets tired of his shit and dumps him, J.D. still remains very much in love with her, which makes it this trope.
- Downplayed in Hamilton: Burr briefly shows attraction to the Schuyler sisters (primarily Angelica) in "The Schuyler Sisters" and "A Winter's Ball", but the subject is pretty much dropped after Alexander and Eliza's marriage. However, Angelica is clearly put off by it (leading to the brilliant line "Burr, you disgust me"/"Ah, so you've discussed me"), which makes it more of a straight example.
- Sinfest's Fuchsia / Criminy romantic subplot started out when the seductive succubus Fuchsia took an interest in Criminy for the purpose of corrupting his innocence. When he treated her kindly, she was reminded of her humanity and developed a crush on him. They gradually started spending more time together, leading to positive Character Development for both of them, as Fuchsia genuinely tried to become the good girl she thought Criminy would like, while Criminy came out of his shell, matured, and arguably Took a Level in Badass for her sake.
- Galgarion from RPG World apparently has some crush on Cherry.
- A spoileriffic but amusing one from Homestuck: Jack Noir, the sort-of Big Bad, has developed a crush on PM, who wants nothing more than his horrible, bloody demise. Given Jack's previous reaction to the entire idea of affection, his response to this realization is to run away.
- In Girl Genius, maybe Zola was faking weakness every time Gil had to rescue her, but her love for him remains after she revealed being way more dangerous than she looks.
- Depending how you interpret him, Tarvek may be this for Agatha (crush undisputed, villainy not certain). And Gil for Agatha as well, but he's rather an Anti-Hero, although recent events out of his control see him shading unwillingly towards He Who Fights Monsters. Given that all four characters thus mentioned are very powerful and not strictly aligned players in European politics, Friend or Foe becomes a complicated question.
- Martellus has one of these on Agatha, although romance doesn't enter into the equation. He's outright stated that he would be perfectly willing to kill her if she interferes with his plans, and the main reason he's chasing her is because of the legend that the Storm King would marry the Heterodyne Girl - she's the Heterodyne, so if he wants to be the Storm King he obviously has to marry her. However, some of his behaviour suggests that he finds her attractive, and he certainly doesn't seem annoyed by the idea of marrying her, with or without her permission.
- Dinah Might from Everyday Heroes seems to be a fan of Mr. Mighty. At first it looks like this is just a distraction to help her and her boss escape; later, though, it looks as if there is some genuine attraction.
- Peridot from Cucumber Quest has a pretty blatant crush on Almond (if you don't believe it, ask Gigi Digi). Being the little brat that she is, she mostly shows it through being Tsundere. Almond is very aware and likes to toy with her about it.
Almond: You just can't stay away, can you?Peridot: Sh-SHUT UP!
- Hyde's constant flirting and occasional advances in The Search For Henry Jekyll really make Al confused and uncomfortable.
- Dr. Horrible, of Dr. Horrible's Sing-Along Blog, has a crush on a local do-gooder, but his arch-nemesis hero beats him to the punch. Unusually, Dr. Horrible is more of a Well-Intentioned Extremist, while the so-called hero is an arrogant bully who only dates the girl to make the protagonist jealous.
- In Death Note: The Abridged Series (kpts4tv), Light has an obvious crush on L. L, for his part, takes full advantage of this and agrees to go out with him for the investigation.
Light: Well, we've been outside talking for awhile and we've decided to make it official. I LOVE L! AND HE LOVES ME! I'm going to dump Misa so I can be with L!Everyone: Gasp
- In keeping with her role as sex goddess of TGWTG, Ask That Guy with the Glasses is implied to have a crush on Allison Pregler (not so much since he fired her IRL). He's also slept with Anti-Hero champion of the universe Linkara.
- Friendship is Witchcraft has Pinkie Pie and Fluttershy as a Shout-Out to Esmeralda and Frollo. Pinkie is a Hot Gypsy Woman while Fluttershy is the cult leader of a Religion of Evil.
- Resident Evil Abridged: In a scene after the credits, Chris finds a document that turns out to be a fanfic written by his traitorous captain, Wesker. He gets two pages in before it starts to get explicit, prompting Chris to draw his gun and shoot it out of revulsion.
- RWBY: In "Alone Together", it's revealed that Ilia fell for Blake around the same time Blake was falling for Adam, and has been deeply jealous of this fact for a while now. She seems to still hold some feelings for Blake as she blushed when finally admitting them, but they aren't enough for her to side with Blake over the White Fang. Ultimately, she does side with Blake, due to several factors, including her love for Blake, her knowledge that she's doing something terrible, and Ghira rescuing her from being crushed.
- Twig: Sylvester's feelings gradually shifts from subtle, to finally admitting that he doesn't see a difference between admiring someone for their abilities and being romantically attracted to them. Meaning that, yes, he's been crushing on his recurring enemies Genevieve Fray and Reverend Mauer.
- The Ice King in Adventure Time would be a very extreme case of this. Early on in the show, he was known for kidnapping numerous princesses and try to force them to marry him, with Princess Bubblegum being his main victim.
- Avatar: The Last Airbender: Ty Lee's one-sided crush on Sokka was an amicable example, since he was flattered by it in "The Drill" episode. Though he later tells her that he was already seeing Suki, in "The Crossroads of Destiny".
- Princess Attea towards Ben in his Incursean form Bullfrag in Ben 10: Omniverse. To Ben's chagrin, the feeling is mutual as Bullfrag.
- Martian Queen towards Duck Dodgers. Seriously, the woman veers between wanting to destroy him and wanting to marry him.
- Gravity Falls
- This happened to Mabel Pines twice, the first being Norman/Jeff which turned out to actually be a colony of gnomes that want her to be their queen by marrying all 1,000 of them and the creepy 9-going-on-10 year old Phony Psychic Mystery Shack rival Gideon (who tends to lean more towards a Stalker with a Crush).
- Giffany might also count, but Soos did return her affection. That is, until she became a total Yandere.
- Looney Tunes. A 1935 Merrie Melodies short, The Little Dutch Plate subverts it. The villainous Vinegar Bottle (all the characters are household items) who has been pursuing the Girl on the Little Dutch Plate gets in a fight with the hero (a little Dutch boy saltshaker), who literally knocks his block off (Vinegar's head is just a bottlestopper, after all). Looking for his head, he accidentally puts on a girlish one from a perfume bottle. The Girl sees his new Pretty Boy looks and immediately defends him from the Boy, walking off with him while cooing "You handsome man!"
- One time on The Simpsons Marge got a job at the nuclear plant and Mr. Burns developed a thing for her.
- The G.I. Joe: A Real American Hero episode "The Gamemaster" not only hints that Zartan has something like this towards Scarlett, but that she reciprocates it!
- In the "Super Powers Team" incarnation of Superfriends, Darkseid had a crush on Wonder Woman and constantly tried to make her his bride.
- In one episode of Teen Titans, Red X flirted with Starfire after pinning her to the wall with one of his gadgets, calling her "cutie" and remarking that the "only crime" between them was that they hadn't gone on a date. (Her only response was to blast him with her starbolts through her eyes.)
- Pyro once tried making a pass at Rogue in X-Men. She replied by throwing him through the wall as a non-subtle "No".
- Teenage Mutant Ninja Turtles
- Agent Bishop is very affectionate towards Karai when he has her captured in Teenage Mutant Ninja Turtles (2003) (despite his threat to Shredder to chop her into "a supersized pile of Highland julienne fries" if his demands aren't met), spending half the episode kicking the asses of Hun and the Turtles, and the other half admiring Karai and going on about how lovely she is.
- While we're talking about the Turtles, in Teenage Mutant Ninja Turtles (1987), the Shredder seemed to have a thing for April.
- Played for Laughs on WordGirl, with Tobey McCallister's crush on the titular character. She almost always rebuffs him, but there are some cases of legitimate Ship Tease between them.