In the direct-to-video sequel Aladdin and the King of Thieves, Aladdin discovers his father is the leader of the Forty Thieves.
How to Train Your Dragon 2 has Hiccup learn of a mysterious dragon rider who has been stealing dragons from another tribe of dragon riders; when he winds up captured by this person, he discovers that it's his long-lost and presumed-dead mother.
Coco: Miguel discovers that his idol, Ernesto de la Cruz, is actually a fraud who murdered his real great-great-grandfather, Héctor, and that his family banned music because Héctor walked out on them to become a famous musician all those years ago. Unbeknownst to them, Héctor had every intention of coming back.
Parodied with a Buzz Lightyear action figure (not the main one) and his archnemesis Evil Emperor Zurg reenacting a slightly modified version of the Star Wars reveal, complete with an (intentionally) overdramatic Big "NO!" and a Skyward Scream.
Zurg: Surrender, Buzz Lightyear! I have won! Buzz: I'll never give in! You killed my father! Zurg: No, Buzz, I am your father! Buzz:NOOOOOOOOOOOOO!
Zurg: Go long, Buzzy! Buzz: Oh, you're a great dad! Yippee!
Live-Action
The big reveal in Angel Heart where Harry Angel is revealed to be Johnny Favorite, and therefore the father of Epiphany Proudfoot, who he has been having sex with, and has just murdered during a blackout, in a rather bizarre set of supernatural circumstances.
Parodied in Austin Powers: The Spy Who Shagged Me with Dr. Evil claiming to be Austin's father (in an exaggerated voice akin to Vader's) and then admitting almost immediately that he was just making it up. In a twist, the third movie features the revelation that Austin and Dr. Evil were in fact brothers, separated as infants.
In the parody Backfire!, the Most Evil Man reveals this to the heroes, complete with Darth Vader voice.
Near the end of Big Money Rustlas, before dying of a gunshot wound inflicted onto him by Sugar Wolf, the film's villain, Big Baby Chips, reveals to Sugar Wolf that he is actually his father, Grizzly Wolf, prompting Sugar Wolf to rub off his face paint to see if he was telling the truth. He was.
In Black Angel Vol. 1, Ikko discovers fairly late that Chiaki, the woman she is trying to kill is, is not her half-sister but actually her mother. In this case, neither woman knew this initally because Ikko was a Child by Rape and Chiaki's father removed the child at birth, telling Chiaki the child had died, and gave it to his mistress to raise.
Bloodthirsty: Vaughn reveals to Grey he's her father late in the film, with his wife Greta her mother who gave her up for adoption so she'd be kept from him.
In the movie The Boondock Saints, the hitman known as Il Duce, who previously gave the MacManus brothers the fight of their lives, is revealed to be their long-lost father when he walks in on them delivering the family prayer to their fallen comrade Rocco (whom he had previously been hired to kill) and finishes the prayer himself. And then much ass was kicked.
Candyman: Farewell to the Flesh has the main protagonist Annie discover that she is the great-great-granddaughter of the Candyman.
In the 2003 film version of the Filipino superhero Captain Barbell, the Big BadLagablab, reveals he is Enteng's (Captain Barbell's mortal alter-ego) Disappeared Dad. Captain Barbell is shocked but defeats him anyway.
The Count of Monte Cristo has Albert revealed as the son of Edmond, conceived right before Edmond is framed for treason and shipped off to prison 16 years earlier.
Taken to ridiculous extremes in Dirty Work. Mitch and Sam are talking to Sam's father, Pops, who reveals he's also Mitch's father. They don't believe him; so he pulls out a locket:
Mitch: That's you and my Mom!... having sex! Sam: You were unfaithful to my mom! Pops: No I wasn't. Who do you think took the picture? (later) Sam: Hey, Mitch, remember when you had sex with my sister?
At the end of Deep in the Valley, Lester and Carl go to Diamond Jim's pool party where Carl decides to get transported home and Lester decides to stay. It is revealed that Lester is Diamond Jim's son.
It is pretty obvious in the French 1961 film Le Fils de Caroline Chérie that Juan is the son of Caroline and Gaston de Salanches, but the characters themselves don't find this out until the last fifteen minutes.
Parodied in Hercules Returns. Testiculi's father refuses to let him marry Uptown Girl Labia. When Testiculi demands to know why, he takes his son aside and reveals that he once slept with her mother.
Near the beginning of Kingdom of Heaven, Godfrey reveals to Balian that Balian is his illegitimate son. The theatrical cut has him outright dropping the trope name, although even before that, it's fairly clear where he's going with the lead-up; the director's cut drops the line, leaving the revelation slightly more implied, but again, it's not hard to understand what he's saying.
Theatrical cut version: I...knew your mother. To be courteous, I should say that it was against her objections, but I did not force her. I loved her in my way. (Beat) Balian, I'm your father.
Director's cut version: I...knew your mother. To be courteous, I should say that it was against her objections... but I did not force her. (Beat) I have forgiveness to ask of you.
Lou. The title character is helping Hannah track down her abusive ex-husband Philip who has kidnapped their daughter Vee. Halfway through the movie we discover that Philip is Lou's estranged son. Hannah is understandably furious not least because Lou, while secretly protecting Vee, has not made the slightest effort to bond with her granddaughter.
The Man from Earth: in the end what confirms that John wasn't lying about his claims to be an ageless immortal was when Gruber (a colleague of John's who appears to be about twice John's age) realized that John is his father. (John had suddenly left his family at the time when Gruber was just a few years old.) The shock ends up giving Gruber a heart attack and he dies shortly after.
Before dying at the end of The Man in the Iron Mask, D'Artagnan barely has the time to reveal to Philippe (and Louis) that he is their father.
The climax of Mortal Engines offers the heavy implication that, like in the books, Thaddeus Valentine is Hester Shaw's biological father, showing that he and her mother Pandora were romantically involved in the past, as well as him directly comparing her own personal drive and determination to his.
In Mr. Deeds, it's revealed that the family butler, Emilio is Preston Blake's son by way of Blake's cleaning lady, and thus heir to his company and fortune.
Subverted masterfully in the movie Pirate Radio, throughout most of which it is implied that Quinten is Young Carl's father, only for it to be revealed by Young Carl's mother that Bob, the 3-6 am DJ is his father instead. Quaintly enough, Young Carl's reaction is eerily similar to that of the trope namers.
Please Turn Over: While Blanche eavesdrops on Rita and Uncle Willie in Naked Revolt, she learns about more than just their affair:
Rita: Who are you to tell me how to bring up my own daughter? You're not her mother.
In Shocker, the main villain reveals himself to be the protagonist's father before he is executed in the electric chair and is turned into a Psycho Electro.
In The Smurfs 2, Gargamel quotes the full line to Smurfette: "I am your father. Search your feelings, you know it to be true".
Sorceress: Traigon tells Mira his name when she's brought before him. She reacts violently, knowing that he's the one who killed her mother, but then is shocked when he reveals that he's her father.
Dark Helmet: I am your father's brother's nephew's cousin's former roommate! Lone Starr: What does that make us? Dark Helmet: Absolutely nothing, which is what you are about to become!
That would potentially make him either Lone Starr's former roommate, his cousin's former roommate or Lone Starr's brother's former roommate (assuming he has one); if, however, the nephew or cousin was from a different side of the family (for instance, if the brother's nephew was a spouse's sibling's child), then Dark Helmet would be correct that this makes them "absolutely nothing" to each other.
In Stardust the servant Una is revealed to be Tristan's mother, and long-lost princess of Storrmhold, making him the heir and king.
This is the Trope Namer and The Reveal from the second part of the original trilogy.note The line as it's frequently quoted is actually Beam Me Up, Scotty!; the radio and Marvel Comics adaptations do render it as "No, Luke, I am your father", however. The reason that this reveal worked and a lot of the imitators fell flat was that a big part of Luke's story revolved around his Jedi Knight father, whom he sought to emulate as a Jedi himself, which was why Luke let out the Big "NO!" in response to the Awful Truth about said father being revealed. In addition to that, this also means that both Obi-Wan and Yoda had been lying to him ever since they met. It also gives new light to Uncle Owen's reasons for refusing to let Luke accept the Call to Adventure, in particular Aunt Beru's assessment that "he's got too much of his father in him" and Owen's response "That's what I'm afraid of". Also, the reveal in Return of the Jedi is that Leia is Luke's sister.
According to The Other Wiki, this was meant to be played again in Revenge of the Sith, where Palpatine would tell Anakin that he created him from midichlorians, before Lucas heavily changed the script, although the implication that Plagueis created him was nonetheless present. It was nonetheless implied that Palpatine was at least somewhat involved alongside Plagueis in manipulating the midichlorians into creating him in the Legends novel Darth Plagueis, although Anakin's creation was actually not just an accident (they were intending to manipulate them into creating a Sith weapon), but they struck back and created the very means to destroy them.
A subversion happens in The Last Jedi, where for the entire movie and the one previous, it was hinted that Rey had some familial connection to someone important (perhaps even a prominent character in the series). In the end, though, Kylo Ren reveals to Rey her parents' true identity: They were "nobodies", just lowly junk traders who sold her for drinking money and are long dead by now.
Ultimately played straight by The Rise of Skywalker, where Rey is Palpatine's granddaughter, via her father. Rey's parents being nobodies was an attempt to hide her from him.
Transamerica: when Toby, a teen runaway who had made a living as a hustler and who seems to only show affection sexually, attempts to seduce the Transgender woman, Bree, who is adopting him, her only recourse is explain him that she was, in fact, his father before transitioning. She'd kept it secret from him because she knew he thought his father was a famous actor and didn't want to disillusion him. The fact that the audience already knows this is a considerable source of Squick in the scene.
Inverted in TRON: Legacy when Sam Flynn seems to finally find his lost father on the Grid; it turns out only to be a program written by Dad, though the dialog is almost verbatim.
CLU: I'm not your father, Sam. But I'm very, very happy to see you.
In the film Wanted, this is used as the twist about 3/4ths of the way through the film. It actually makes sense, because it's the only reasonable explanation for why Cross never seems to be able to hit Wesley despite his improbable superpowered gun skills; turns out he was never trying to kill him in the first place.
Implied in Warcraft. Garona, a half-orc, talks about her orc mother dying shortly after giving birth to her. Later, the human Medivh talks to Garona about love and drops some heavy hints that he fell in love with her mother and is her father.
