- Romeo and Juliet are perhaps the most famous example. Also invoked, as both characters are teenagers and would likely qualify more as Puppy Love, but the Feuding Families turn them into Star-Crossed Lovers.
- In Measure for Measure, this happens to the antagonist, Angelo, after he first meets the protagonist, Isabella.
- More happily, in As You Like It, Orlando and Rosalind, and later Oliver and Celia, fall in love at first sight. The trope gets lampshaded and even deconstructed, but it's ultimately shown in a positive light.
- In The Taming of the Shrew, Lucentio falls in love with Bianca at first sight. His servant, Tranio, lampshades it."I pray, sir, tell me, is it possible
That love should of a sudden take such hold?"
- In Les Misérables, Marius and Cosette fall in love when Marius, chasing after Eponine, alternately walks into Cosette or knocks her basket off her arm. "I didn't see you there, forgive me," might be the best pickup line ever because suddenly both of them are in love with each other and manage to sing several songs about it before discovering what the other's name is.
- Played sort-of straight in Sweeney Todd: The Demon Barber of Fleet Street between Johanna and Anthony, the latter of whom expresses his feelings repeatedly in a supposedly romantic song that sounds a lot like something John Hinckley Jr. would sing to Jodie Foster. This is Stephen Sondheim, so the ridiculousness is also parodied in "Kiss Me", a song about the two running away from Judge Turpin before he forces Johanna into marriage. This little ditty features such lines as "I knew I'd be with you one day, even not knowing who you were" with Johanna's expression becoming momentarily confused as to how precisely this guy is the love of her life when she's only just met him, a fact underlined by the later line that clearly states (even though they're eloping) that she doesn't even know his name.
- Under the circumstances, Johanna is being fairly practical. Anthony offers her a way out of marrying Judge Turpin, and she accepts it. After all, she doesn't have a lot of options. Besides, Anthony is quite possibly the first young man she's ever met. Naturally she's interested in him. Her desperation, loneliness, and curiosity might not equal love; she might be dressing up her feelings to make the best of a less-than-ideal situation.
- The Judge Turpin falls in lust at first sight for Lucy.
- Although it's a staple of the original fairytale, it's perhaps even more pronounced in the Rodgers and Hammerstein musical of Cinderella - in the 1957 version, Jon Cypher looks like he's just been hit with a very large truck, and Paolo Montalban in the '97 edition looks like the floor has just dropped out from underneath him. Somehow, both of them actually manage to make it believable, too. The 1960's version averts this though.
- Receives a Take That! in Cyrano de Bergerac:Roxane: Well, I love him. That is all Oh—and I never saw him anywhere except the Comédie.
Cyrano: You have never spoken?
Roxane: Only our eyes.
Cyrano: Why, then, how do you know?
Roxane: ... I know.
Cyrano: So soon! So soon we lose our hearts! But, my dear child ... You, who love only words, wit, the grand manner — why, for all you know, the man may be a savage, or a fool.
Roxane: His curls are like a hero from D'Urfé.
Cyrano: His mind may be as curly as his hair.
Roxane: Not with such eyes. I read his soul in them.
Cyrano: Yes, all our souls are written in our eyes!
- Me and My Dick has a subversion. Dick and Miss Cooter fall in love at first touch when Joey and Sally hug too close.
- Happens to Tony and Maria at the dance in West Side Story. Not surprising given it is a Setting Update of Romeo And Juliet.
- Show Boat has Ravenal and Magnolia meeting and singing a love song during the first scene, though she's shy about it and he conveniently pretends that he's only acting. Her timely but winsome interruption of his solo number, "Where's the Mate for Me?", promises quite enough.
- Natasha, Pierre, and the Great Comet of 1812 has Natasha Rostova experiencing this twice in the musical——in No One Else she sings about how when she first saw Andrey, she fell in love with him. Later, when she prepares to elope with Anatole, Sonya voices her frustration:But I can't believe what I don't understand: how you loved one man a whole year, and suddenly——you've only known him three days, Natasha, you're joking!
- Averted by her eventual romance and husband, Pierre Bezukov, whom she has known since childhood but never considered a romantic prospect.
Love At First Sight / Theatre