Luke, You Are My Father

Finding out parentage in a story can be shocking to characters, but so is finding out they are a parent. A character comes along, and suddenly turns out to be either a long lost child, or a child a character never knew he had (since it has to be a guy unless Rule of Funny comes into play). This is what you get when a Missing Mom or Disappeared Dad had no idea they were one in the first place.

This is of course the inverse of Luke, I Am Your Father. Compare Separated at Birth, Luke, I Might Be Your Father. May result in Sink-or-Swim Fatherhood. This is a Reveal Trope, so Spoilers will be coming your way.

Anime & Manga

 * Solty Rei Roy Revant's daughter Rita Revont
 * Angel Sanctuary. Angels aren't allowed to have children, so Zaphikel brings his child's fetus to the breeding machine, to make it pass for a legal, artificially made angel. He's too late, the fetus is dead, so he tries to kill himself. Then Adam Kadmon shows up and saves him, but the sight of such a glorious creature leaves him blind. Years later, Adam Kadmon shows again and restores his sight, he takes a glimpse at his then asistant, Raziel, and instantly realizes that he is his son, Adam Kadmon had resurrected him back then and he didn't notice because he was blind.
 * The entire premise of Otaku no Musume San, where Kouta first learns he has a daughter, Kanau, when she shows up on his doorstep, with a note from her mother reminding him of a certain eventful afternoon about ten years before. Eventually it starts turning out that everyone is "related", too (mostly through things like adoption,, and friendship), though it's one case that's not much connected to this trope.
 * Jo Jos Bizarre Adventure does this three times: Josuke, the protagonist of part 4, is part 2 hero Joseph's long-lost son. Giorno Giovanna, protagonist of part 5, is the son of Dio Brando, and in part 6 we meet Dio's other sons.
 * DBZ -- Trunks, anyone? Vegeta must be so proud to have a son that is the official Estrogen Brigade Bait of the series.
 * The true Big Bad of the X Men anime is revealed in episode 12 to be
 * In Fairy Tail, Cana's motivation for passing the S-class exam is so she can work up the nerve to tell that she is his daughter.
 * In Mahou Sensei Negima, the main antagonist of the Festival Arc is, who is eventually revealed to be a descendent of Negi's from 50 years in the future.

Comics

 * Connor Hawke, the second Green Arrow, showed up in the '90s as the son the first Green Arrow, Ollie Queen, never knew he had. Retcons have since established that Oliver actually did know, and Connor knew Oliver knew, although Oliver didn't know that Connor knew Oliver knew. All clear?
 * Wolverine turned out to have both a gender-swapped clone (Laura Kinney, aka X-23), and a long-lost son, Daken. The new Scorpion is the daughter of villainess Monica Rappaccini, probably fathered by Bruce Banner (aka the Hulk).
 * Speaking of the Hulk, he also has his son Skaar, who was still in his mother's womb when she died, as well as Lyra, his daughter by Thundra from a divergent future.
 * There's also Skaar's twin, Hiro-Kala. Neither Hulk or Skaar know about him yet, but he's making his way to Earth...
 * Semi-Lampshaded in the newspaper comic strip FoxTrot, in which young nerd Jason campaigns for Lucasfilm to digitally insert him into the Special-Edition Star Wars films as Luke's younger brother. Obviously, this goes nowhere. ("At least they sent back my Darth Jason prototype action figure.")
 * Darth Jason?
 * Wildcat IV in Justice Society of America.
 * The JSA has a bit of a habit of this. Jade and Obsidian pulled this one on Green Lantern (Alan Scott) when they were first introduced back in The Eighties.
 * Captain Boomerang II in Identity Crisis. Includes the literal line, as when Captain Boomerang tracked down his son, put up for adoption, he lost his nerve at the last moment -- too late to prevent his son from seeing him and making the jump.
 * The Trickster in the DC Universe once went to help an ex-girlfriend whose son was in danger. After protecting him from the demonic Neron, he did the arithmetic to realize who the father had to be.
 * Darkdevil in Spider-Girl, who is revealed to the reader - but not the heroine or her family, yet - to be the son of Ben Reilly, Spider-Man's clone.
 * In the new Booster Gold comics in which Rip Hunter, a character first introduced in the DCU in the 1950's, bullies Booster into being an unknown hero, there've been strong hints that  Try not to think about causality too hard. Booster himself also crashes at his great-great-great-etc grandfather's house.
 * Tossed in a blender with Luke, I Am Your Father (but not really) in Usagi Yojimbo:  TL;DR: Father A and Son B know the truth, but each doesn't know the other knows the truth (C,D,E, and F know the truth too, but they aren't talking, mainly out of respect).
 * In Green Lantern Corps #35, it's revealed that is Sinestro's daughter.
 * in "The Long Cold Dark", Frank Castle discovers that .  . Needless to say, Frank was pissed.
 * During the "Salvation" arc or Preacher (Comic Book) Jesse becomes acquainted with a woman named Jodie, whose demeanor and appearance bears an uncanny resemblance to the deceased Jody from previous arc "All in the Family." Jesse begins to feel that something is amiss about Jodie beyond the obvious the more time he spends with her, until it finally hits him one night while alone with her in her bar and he can only say one word:
 * In Batman, Damian Wayne, son of Bruce Wayne and Talia al-Ghul, was raised in the League of Shadows since birth with his father never knowing about him until years later.
 * He made his grand entrance by beating the shit out of Tim Drake, the current Robin, in the apparent belief this would make him Robin. (Jason Todd expressed his return to life by beating up Tim. Tim is kind of the Butt Monkey of the batfamily, which is saying something since Jason got killed and Barbara crippled.)
 * Damian was retconned into being a Child of Rape via Talia drugging Bruce, and then, by the way, she put him into an Artificial Womb as soon as possible so being pregnant wouldn't have the chance to ruin her body. (It often does that and she's put everything into her physical prowess.) This comes up when it turns out she's given him up as corrupted by Batman's ethics and is replacing him with a clone.
 * In Young Avengers Presents: Hulkling, Hulkling does this to

Fairy Tales

 * In The False Prince And The True, a young man on trial for his life after striking the prince reveals at the trial that the queen had actually passed off a quarryman's son as hers, and the king's, while he himself was the offspring of the king by a secret marriage.

Fanfic

 * When Asa in Futari wa Pretty Cure Blue Moon first starts to wonder about Enigmatic Minion Mekuramast's true motives, her initial conclusion is that he's her Disappeared Dad, and she confronts him about this. As this theory is purely born of Asa's Wrong Genre Savvy and, more to the point, makes no sense, it's quickly refuted, and he spends the rest of the story thinking she's a nutcase.
 * Day 1 of One Hundred Days has Warp Darkmatter telling unmarried and virginal Buzz Lightyear and Mira Nova that they're his parents, and he has proof to boot. Turns out, he's right!

Film

 * Wasabi: Jean Reno's character discovers he has a Japanese daughter.
 * Kill Bill's Twist Ending, in which Beatrix Kiddo discovers that.
 * Un Indien dans la Ville, and its English-language remake, Jungle 2 Jungle
 * As Indiana Jones and Marion Ravenwood are sinking into sand in Indiana Jones and the Kingdom of the Crystal Skull, It's also Luke, I Am Your Father at the same time.
 * In The Long Kiss Goodnight, the Big Bad is about to leave Charlie and her young daughter to freeze to death in a meat locker. Charlie, in an attempt to save her daughter, reveals to him that her daughter is also his daughter. He leaves them both in the locker, anyway.
 * Oldboy features a particularly cruel example: the main character is the victim of an elaborate revenge/imprisonment plot, the final result of which leads him to discover that
 * A rather unnerving example serves as The Reveal in the slasher film Cherry Falls. The Serial Killer targeting virgins  is strongly implied to be.
 * "Dad?"
 * "I'm not your father, Sam... but I'm very, very happy to see you."
 * to Wilbur from Meet the Robinsons.
 * The main plot of Matchstick Men revolves around this.
 * Aladdin and the King of Thieves: Happens when Aladdin meets his father Cassim. Cassim is convinced by the dagger Aladdin is carrying - he had left it with his wife to give to their son when he was old enough.

Literature

 * Averted in many, many ways in Legacy of the Force, ironically with the prospective father being Luke: Luke and Mara think that "Brisha"'s mother is Luke's ex-girlfriend Shira Brie. Mara asks Luke "Who is Brisha's father?" Luke replies "How should I know?", realizes what Mara's asking, and says their relationship was emotional (even if it was based on her lies that almost got him killed) and never physical.
 * Dirk Pitt ended up with twins after it emerged that his girlfriend hadn't actually died. He becomes a good father really quickly.
 * In a Star Trek Expanded Universe novel, the character Xyon is introduced at the beginning of the story and helps save the day. At the end, he punches out The Captain Mackenzie Calhoun before informing him his full name is Xyon of Calhoun. Nice first impression.
 * William Butler Yeats wrote a poem in which Cuchulainn's son leaves home with a vow (apparently designed to give him extra chances to get into fights) not to give his name but at the sword-point, that is, after being beaten, and only against someone who's sworn the same. He runs into Cuchulainn in short order, and as Cuchulainn has been under the same oath since childhood they have an epic fight. Cuchulainn gives him a chance to withdraw and live, and says his head looks like 'a woman's head that I loved once.' Then he gets into his berserk mode and mortally wounds him, and demands his name before he dies. And he's Cuchulainn son of Cuchulainn. He is stricken. The people he was partying with earlier predict that once he's done mourning he'll kill everybody to work off his feelings, so they get the druids to enchant him so he gets in a fight with the ocean instead.
 * The poem is Cuchulainn's Fight With the Sea, and is extra head-banging in that it was Junior's mother who told him to make the vow and go to the precise place Cuchulainn was to be found, thereby guaranteeing them a fight in which the father didn't know he was killing his son. Apparently based on an actual myth/saga thing in which this happened to Cuchulainn, only in this one his wife was actively trying to get revenge on him for leaving her through their son.
 * Random does this to Arthur Dent in Mostly Harmless of the Hitch Hikers Guide to The Galaxy series.
 * The Dresden Files: Given the spoilers for Changes,  is going to get a good dose of this.
 * In Brandon Sanderson's Mistborn, Vin identifies her long-lost father, since her brother had pointed him out to her. The father didn't know she existed until she pointed him out to his boss.
 * In some versions of the Arthurian mythology, Mordred is the son of Arthur and his sister, who was sent away to die as an infant, as he was destinied to kill Arthur later on. Which he did when he showed up as an adult.
 * Kafka on the Shore, a novel by Haruki Murakami. The relationship is not spelled out but rather strongly implied, in the manner of: "Are you my mother?", "Why, you have to ask?"
 * In Michael Crichton's novel Next, one random story involves a man working I can't remember where. A young woman with a baby walks up to him and claims to be his daughter. Naturally, he doesn't believe her. She then reveals that she went through a long and arduous process to find out who donated sperm to her mother, despite the fact that it was supposed to be anonymous, spending years just to discover her dad. And then berates him for donating "defective DNA."
 * The novel Sunrise in the Warrior Cats series when announces not only to her father,, but to the whole gathering of cats that  are actually.
 * In The Book of Amber, this happens to Random, as well as to Benedict (who finds he has a great-granddaughter, Dara), and Corwin (who finds he now has a son by Dara).
 * Fred Vargas' Commissaire Jean-Baptiste Adamsberg has a one year-old son with Camille, but also a twenty-seven year-old son, Armel, whose existence he ignored until Armel, at the time believed to be the Zerquetscher, told him while threatening him with a gun in An Uncertain Place.
 * Averted in Dragons of Summer Flame by a character raised by a race of island dwelling fae who is mistaken for Raistlin Majere's daughter. She seeks him out, who promptly tells her she's mistaken.
 * In Michael Flynn's Up Jim River, Donovan is in denial, and the harper doesn't want to talk about once she realizes. When Donovan puts it together, the conversation that ensues has both this, and Luke, I Am Your Father.

Live Action TV

 * in Lost. Oh, come on, we all knew the moment the name came up.
 * ''MacGyver'
 * In Star Trek, both Kirk and Picard had plots where they discovered their sons. Picard's son wasn't, Kirk's was (and Kirk knew about him, but the audience sure didn't).
 * Worf also got two (sort of), the first in which he had no idea his one night stand with the half-Klingon ambassador had any results and then she showed up with their son, and the second in DS9 when said son shows up to serve the Klingon Defense Forces on Worf's ship with no warning.
 * In DS9, a subversion occurs. Garak can only get Tain to drop the superior officer/inferior officer and mentor/protégé "formalities" of their relationship and behave as a genuine father and son when Tain is on his deathbed and even then Garak has to fight Tain into submission over it. The subversion comes from the fact that Tain and Garak have known the true situation between them for Garak's entire life, but there was no public acknowledgement of it because Tain feared having a biological son was a weakness someone in his position couldn't afford. He uses his dying breath to admit he was proud of Garak which is all Garak really wanted to know.
 * Subversion, maybe: In a Supernatural episode, Dean goes to revisit the site of a 9-years-ago one-night stand and discovers that the woman has an 8-year-old son with remarkably Dean-like mannerisms. She swears the kid isn't his, and claims that DNA evidence proves it, although it is not actually presented to him. The creator later confirmed that the kid wasn't Dean's son.
 * A variation in Season 4, where a guy a few years younger than Sam and Dean shows up claiming to be John Winchester's son.
 * sure fixed that. Don't look like that, It Got Worse.
 * And then again in Season 7 in which it's played straight.
 * Red Dwarf did a weird variant on this where Lister ended up fathering a kid...who later turned out to be himself through Applied Phlebotinum time travel. (Don't ask. It's Red Dwarf. What do you want, logic?)
 * This is likely based on Robert A. Heinlein's famous Stable Time Loop story —All You Zombies—, about a time traveling who ends up being   Time travel can be like that.
 * There's another example of Luke, You Are My Father in the Red Dwarf novel Last Human, with the character Michael McGruder.
 * Law and Order: Criminal Intent: Bobby Goren has just discovered he has a nephew (son of his junkie brother Frank.) Bobby wants to parent the kid but the kid is currently missing and on the run from the cops. Bobby's family is messed up.
 * On Gilmore Girls, there is a situation which could be (but isn't) the source of this trope name. A girl shows up in Luke's diner saying she is doing a science fair project in genetics to find out who her father is by testing the three guys her mother dated around the time she was conceived. It turns out Luke is her father. This is used to derail the upcoming wedding. Lorelai's father semi-lampshades this when discussing insurance with them and warning about tricksters and grifters, saying "It's just that the timing is a little suspicious..."
 * Daniel Meade of Ugly Betty recently discovered that he had a son.
 * And then by the end of series, both were.
 * Beverly Hills: 90210: Gina was introduced in the later seasons as Donna's wrong-side-of-the-tracks cousin related through her mother's sister. With the help of some nifty software that included every single birth certificate ever made, Donna discovered.
 * Earth: Final Conflict: Liam "Kincaid" is the Child by Rape of Agents Sandoval and Beckett by Ha'Gel. He knows this, but his mother was mind-wiped to prevent her from exposing the Resistance. Beckett only finds out when she's dying from a CVI breakdown. It's a good question as to whether or not Sandoval figured it out.
 * On Vampire Diaries Elena discovers  and uses this knowledge in a confrontation to force him to let her go.
 * Home and Away added an extra twist: John Palmer has a daughter named Shandi, but the Shandi he met was an imposter. Eventually, the real Shandi had to show up.
 * At the end of the second series of Merlin, Merlin meets his long-lost father, Balinor, for the first time. Balinor had no idea he had a son.
 * In the French series Les Bleus, Premiers Pas dans la Police, rookie detective Laura Maurier is the daughter that police chief Santamaria never knew he had, and she eventually tells him so.
 * In the new series of Doctor Who, in the sixth series episode "A Good Man Goes To War,"
 * There's also Rose going back to when she was a baby and saving her father. She has to fend off some flirting from him right at the start, but he eventually figures it out more or less on his own. Later, after overhearing that the nineteen-year-old Rose is Pete's daughter but missing the "from the future" part, her mother is understandably squicked by the appearance that her husband a) fathered a child when he was about twelve and b) gave her the same name as the baby they currently have together.
 * Then Rose crosses over into a parallel universe where Pete's alive but never fathered a child with Jackie, and we go through it all again, this time with Pete having to come to terms with the fact that he has a daughter in a parallel universe with the same name as his dog.
 * In one episode of Fresh Prince of Bel Air, a young man appears at the Banks' doorstep and introduces himself as Geoffrey's son. Apparently Geoffrey's ex-wife had given birth to him after their divorce and didn't bother to inform Geoffrey.
 * In an episode of The Ropers, a 30 year old man tells Stanley that he is his son.
 * The protagonist of Life Unexpected is a 16 year old girl that was never succesfuly adopted that seeks emancipation and reunites her birth parents who a judge makes them their legal wards after deeming she is unfit to be emancipated, her father thought she had been aborted and when he was told in the first episode he had a daughter it was an instance of this, the girl's father is just a friend of the girl's mother as she has a fiance of her own.
 * CSI: Miami, Horatio and his son.
 * In the mini-series The Tenth Kingdom, a gender-flipped version occurs.
 * What kicks off Once Upon a Time is that Emma makes a wish to stop being alone. Seconds after had she blown out her candle, she gets a knock on the door and one trouble-making little boy going "Hi Mom!"
 * What kicks off Once Upon a Time is that Emma makes a wish to stop being alone. Seconds after had she blown out her candle, she gets a knock on the door and one trouble-making little boy going "Hi Mom!"

Music

 * Johnny Cash's Boy Named Sue pulls this on his father, who he is hunting down to kill him for, well, naming him Sue.

Mythology

 * Cuchulain and Connla, in the Ulster cycle of Irish myth.
 * Similar is the story of Sohrab and Rustum. Rustum, the Persian Hercules, has fathered a son but received the news that it was a daughter (so that he would not drag the son off on dangerous adventures). As a young man, Sohrab goes off looking for his father, and ends up fighting against him in a champion-versus-champion confrontation between two warring armies. Sohrab gives out that he is looking for Rustum, but Rustum conceals his identity as he feels it beneath him to be acknowledged fighting a lesser man one-on-one; and also because he thinks Sohrab is only glory-seeking, and will make peace and go away boasting of having met Rustum as an equal. Only after Sohrab is fatally wounded does he learn Rustum's identity and offer his father proof of his ancestry, eventually convincing him. Written up by Victorian poet Matthew Arnold based on the Persian original, see http://www.victorianweb.org/authors/arnold/pva356.html.
 * Older Than Feudalism: In Greek Mythology, Theseus pulls one on Aegeus when the former enters Athens as a badass victorious hero. Aegeus' wife is not very pleased.
 * Various interpretations of Beowulf hint at Grendel being Hroðgar's son and also though never outright stated in the text... Beowulf is the Dragon's father. Explicitly interpreted in the 2007 animated film..

Video Games
"""When I was ...I met  in a dream. I was still little when I was separated from, but I still remember  .   was strong, kind, and gentle...  ... You're my  !""
 * Slightly subverted in Visual Novel Ever 17,
 * Throughout Jade Empire, it's slowly revealed that Dawn Star is Master Li's daughter. When you confront him with this, his response is approximately, "So what?"
 * In Lost Odyssey, the pair of Tagalong Kids that Kaim and company befriend bring the party home to meet their ill mother... who immediately recognizes, making the kids.
 * In Sacred 2, the class-quest of the Inquisitor involves you running into your long-lost daughter, with a number of interesting consequences. Firstly, being a man of the cloth, you're not supposed to have children at all, and so you must keep the matter quiet and kill anyone stupid enough to try and blackmail you about it. And secondly, you have to Pet the Dog and keep your daughter out of the trouble she constantly finds herself in. Funnily enough, when she finally finds out that you're her father, she's... less than pleased.
 * If you didn't kill  when   was your enemy early in the story,   from Thracia 776 recruits   by telling him this.


 * At the end of Metal Gear Solid 4 Guns of the Patriots, gets his happy ending when he learns that
 * In Dragon Age II, Hawke's uncle Gamlen can learn that he has a daughter at the end of the quest "Gamlen's Greatest Treasure".
 * Roger Jr., Roger's son from the future in Space Quest IV.

Webcomics

 * Order of the Stick: Elan's father may have spoofed Luke, I Am Your Father when he showed up, but the actual situation is closer to this trope (considering the character first appeared only one page before the reveal).
 * Well, he did show up in one Flash Back over 600 episodes before that, here, although he wasn't named then and hasn't been seen since. Still, the "reveal" came as no surprise to someone with a good memory.
 * The Inexplicable Adventures of Bob: Jean is a bit insistent that all of the peanut butter monsters generated by her project are, in a sense, her children. Nonetheless, she seems freaked out every time she encounters one for the first time.

Web Original

 * In Runescape Gods Exposed, Iban shows up in one episode saying Zamorak is his father. Gudging by his response this has been going on for a looooong time.

Western Animation

 * Gargoyles - when Goliath and crew arrive in Avalon, he discovers that the eggs that they managed to save from the clan massacre were brought there, hatched, and were all full-grown gargoyles; one of whom is his (and Demona's) daughter, Angela. The comic later points out that Gabriel, Angela's friend on Avalon, is the son of the two Gargoyles that became Coldstone and Coldfire.
 * Although this leads to awkward situations for Goliath and Angela. Gargoyles raise their children in a community with no child being the son or daughter of one specific parent. Angela, being raised primarily by humans, worries a lot about her parentage in comparison.
 * Batman Beyond:  And
 * Luke, I Am Your Father is parodied in Futurama Benders Game with, complete with ripped lines from Star Wars and a lightsaber duel. This was made especially funny by the fact that they were supposed to be ripping off the Fantasy genre, but still managed to slip into sci-fi.
 * The Simpsons had an episode in which Mr. Burns' long-lost son turns up - voiced by (and drawn to look like) Rodney Dangerfield.
 * Later on, Krusty's long-lost daughter shows up.
 * Dermot from The Venture Brothers..
 * In Young Justice the exchange is completely non-verbal and takes about ten seconds. And it's a whammy.
 * Happens again in season 2 at the end of "Salvage" when Jade shows Roy their baby girl Lian.
 * Happens yet again in "Bloodlines" when Bart announces that He's Barry and Iris' grandson from the future.