[[caption-width-right:278:Clearly a man who likes his twist endings.]]

William Sydney Porter (September 11, 1862 June 5, 1910), PenName O. Henry, is an American writer of chiefly short fiction (the most famous piece being "Literature/TheGiftOfTheMagi") and one novel (''Cabbages and Kings''). His stories are famous for their [[MandatoryTwistEnding Mandatory Twist Endings]], warm characterization and wit.

For some inexplicable reason--at least partially having to do with two [[FilmOfTheBook film adaptations]], which are quite good--he is [[GermansLoveDavidHasselhoff most popular in the former USSR republics]], where phrases such as "Bolivar cannot carry double" have become stock quotes.

The "Oh Henry!" candy bar (later associated with Hank Aaron) was partly named in homage to him. (And partly named for a boy who flirted with the girls at the candy factory.)
!!Works by O. Henry with their own trope pages include:

* "Literature/TheGiftOfTheMagi"

!!Other works by O. Henry provide examples of:

* BalloonBelly: Poor [[LazyBum Stuffy Pete]] in "Two Thanksgiving Day Gentlemen", after [[spoiler:he guilt-trips himself into eating two huge Thanksgiving dinners in immediate succession provided by mutually unaware benefactors]]:
---> "Around the first corner Stuffy turned, and stood for one minute. Then he seemed to puff out his rags as an owl puffs out his feathers, and fell to the sidewalk like a sunstricken horse."
* BananaRepublic: ''Cabbages and Kings'' is the TropeNamer.
* BeleagueredChildhoodFriend: ''After 20 Years''.
* BigApplesauce: A popular setting of many of his stories; the short story collection ''The Four Million'' is set there.
* BrattyHalfPint: Johnny Dorset from ''The Ransom of Red Chief''.
* CantGetInTroubleForNuthin: ''The Cop and the Anthem''.
* ConMan: Jeff Peters and Andy Tucker, protagonists in a cycle of stories.
* {{Cowboy}}: Normally of the Working Cowboy varieties, protagonists in many stories.
* CorruptCorporateExecutive: An early example in "Shark" Dodson from ''The Roads We Take''.
* DomesticAbuse: ''A Harlem Tragedy'', which, despite the title and the subject matter, is a very light-hearted story.
* DownerEnding: Occasionally, for example in ''The Furnished Room'' and ''The Last of the Troubadours''.
* ExasperatedPerp: ''The Ransom of Red Chief''.
* FlashSideways: "The Roads We Take" starts as the story of a ruthless criminal who wonders what his life would have been like if he hadn't come West -- then he wakes up, and from then on it's the story of a ruthless businessman who dreamed about what his life would have been like if he hadn't come East.
* IllGirl: ''The Last Leaf''.
* IneffectualSympatheticVillain: ''The Ransom of Red Chief''.
* LetOffByTheDetective: ''A Retrieved Reformation''.
* LukeIAmYourFather:
* MeaningfulEcho: In "The Roads We Take", the paragraph about Dodson revealing his true nature is repeated word for word when the other Dodson turns out to be not so different.
* MockMillionaire: ''Transients In Arcadia''; ''The Policeman O'Roon''
* NiceJobBreakingItHero: ''The Last of the Troubadours''.
* NoNameGiven: What the hell does that "O" stand for?
* PityTheKidnapper: TropeCodifier. In ''The Ransom of Red Chief'' two small-time criminals kidnap a BrattyHalfPint who proves to be so insufferable that the kidnappers end up paying a ransom to his father to take him back.
* StupidCrooks: As mentioned immediately above, the kidnappers in "The Ransom of Red Chief." They're dumb enough to kidnap an obviously evil child, and he's such a terror that they end up having to pay his father to take him back.
* ThatManIsDead: ''A Retrieved Reformation'', in a way.
* TitleDrop: In "The Roads We Take", the protagonist wonders if he'd have turned out a different man if he'd made a key choice differently, and his colleague says "I reckon you'd have ended up about the same... It ain't the roads we take; it's what's inside of us that makes us turn out the way we do." The end of the story bears him out.
* TomatoSurprise: ''After Twenty Years'' has the revelation that [[spoiler:the main character is an infamous criminal.]]
* TrainJob: "The Roads We Take" opens with a trio of Wild West desperados hijacking a train when it stops to take on water.
* TwistEnding
* VillainProtagonist: Because O. Henry spent time in jail, many of his stories, like ''The Ransom of Red Chief'', focus on (relatively) petty criminals.
* WildWest: Another popular setting; usually limited to Texas ranches.