Fantasy-Forbidding Father

A father, mother, or guardian (these last two are less common) disapproves of their child or ward reading "fairy stories", playing fantasy or scifi games, sports, and even such "useless" hobbies as astronomy, boxing and being literate. In extreme cases, anything the child likes that isn't directly and concretely tied to whatever it is their dad does for a living (or that he wants them to do for a living) is seen as an utter waste. The dad may even break, burn or sell anything of this nature their child owns, possibly even punishing or locking them up.

"Fantasy" in this trope isn't about the genre, but "fantasy" from the father's perspective. To the Overprotective Dad, any and all of these "distractions" are a Tragic Dream waiting to happen that will ruin their child's chances at life. For narrative purposes, this is basically anything that the kid likes that'll move the plot forward via alienating them from their dad (possible later reconciliation optional but heartwarming), which puts the Fantasy-Forbidding Father into an antagonist role, though with rare exceptions he is not a true villain.

What's cruelest about this attitude is he probably does hold his child's best interests at heart, but is too close-minded to consider that there are many valid careers and hobbies for their child, and that they are capable of choosing for themselves. In these cases the dad does come around to accepting their child's interests and vocation with a little coaxing. A more sinister possibility is the dad is trying to somehow make their child co-dependent or at least clip their wings so they never leave or get out from under his thumb, either forcing them to follow a family legacy or just out of sheer malice.

See also "Well Done, Son" Guy. Compare Education Mama. A close-minded Caretaker usually takes this attitude.

Examples of Fantasy-Forbidding Father include:

Anime and Manga

In Otomen, the main character Asuka secretly loves knitting, embroidery, cute things, cooking and girls' manga. It's a secret, because Asuka's a guy, and his mother constantly warns him he must be manly, lest he ends up like his father who decided he wanted to be a woman and consequently left Asuka's mother.
Yu-Gi-Oh!: A flashback reveals that Gozaburo asked his adopted Kaiba what he would do if he was in charge of Kaiba Corp. Kaiba says that he wants to make Kaibaland (which is very much like Disneyland) for kids to enjoy. However, Gozaburo is an Arms Dealer, so he is completely unable to comprehend such a thing. So he decided to take away Kaiba's toys. Considering that Gozaburo was very abusive towards Seto Kaiba at least, this would indicate that he simply wanted to keep Seto under his thumb.
Hiroko's father in AKB49: Ren'ai Kinshi Jourei strongly disapproves of her aspiration to become an Idol Singer, which led to a heated confrontation between him and her when he found out that she had joined an idol group.
Genma Saotome often gets this in Fanfic; it's a logical extension of the character's canon attitudes. Most often used in deconstructive/more realistic versions so that Ranma has a credible reason to break away from martial arts and try to do something else with his/her life, because supposedly he'd been bullied into his martial arts excellence unwillingly by Genma.

Comics

Walter of ClanDestine disapproves of Rory and Pandora's superhero aspirations, going so far as to threaten to have them raised separately in order to negate their Wonder Twin Powers until they're adults. However, while he does think that "superhero" is an impractical job choice, he's also worried that they could get hurt—they're twelve years old at this point. There's also the risk that someone could find out about the family through the twins' activities—the last time that happened, two of the Clan died. In this case, the eventual solution is a compromise: the kids get to continue their superhero careers, but only when an adult relative can chaperone them.
The Far Side has a cute inversion: the father's shirt has been grabbed and he's being lifted up by a large (and invisible) assailant, while his son grumbles, "Big Bob is tired of you saying he doesn't exist!"
Dr. Manhattan's Father in Watchmen could be seen as an example, forcing his son to pursue a career as a scientist instead of watchmaker.

Film

Willy Wonka's dad from the new Charlie and the Chocolate Factory movie was like this.
Dead Poets Society - Neil's father thinks anything that could detract from his son's future as a doctor is an utter waste. He goes ballistic when he finds out Neil is playing Puck in A Midsummer Night's Dream. When he punishes him by sending him to military school, Neil is pushed over the edge and takes his own life.
The lord of Swamp Castle in Monty Python and the Holy Grail, who won't let his son sing (or do anything else except marry the girl with great tracts of land that he's picked out).
- Actually the son's not fit for doing much of anything else.
Rad has the mom disapprove of her son's BMX'ing, and doesn't want him to participate in a local competition. The reason? It might interfere with him taking his SAT test months down the line. It wasn't even a question of the son having to balance school and biking, just random opposition to pad the movie.
In School of Rock, Zach's dad forbids him from playing rock music and insists on him only playing assigned classical guitar pieces.
Star Wars: Uncle Owen to Luke Skywalker. In Owen's defense, he was worried Luke would Turn Out Like His Father. Y'know, a galactic scale villain?
Step Brothers: Robert mentions that his dad made him give up being a dinosaur at age seventeen so he could get a job. ("But you're a human. You could never be a dinosaur.")
In Super 8, deputy Jackson Lamb felt his son helping with the costuming and makeup of friend's film hobby was something to be outgrown, and was intending on sending his son to a baseball camp for maladjusted kids. Eventually after a lot of outside pressure piled up on him (and his son befriended the daughter of the man he blamed for his wife's death) he forbade him from associating with them again. Most of this was due to him being emotionally disconnected from his son after his wife's death.
In Disney's Tangled, Mother Gothel kept Rapunzel's desire to leave the tower she was living/prisoner in in check for most of her life by a combination of belittling her and telling terrifying tales of the outside. In this variation, however, Gothel has no interest in protecting Rapunzel's feelings or well-being, and keeping her in the tower is directly related to Gothel's own gain.
In Tenacious D in The Pick of Destiny, Jables' father spanks his son for his reverence of Ronnie James Dio and Rock. Ironically enough, his father happens to be played by Meat Loaf.
In Pan's Labyrinth, Ofelia is chided for reading too many fairy stories when she's supposed to have outgrown them.
In Sister Act II, Rita's mother is determined to squash her dreams of becoming a singer. She won't even allow her to join the school choir as an extra curricular because she thinks she should be spending all her time studying to get into a good college.
- Which is a little misguided, when you consider that college admissions isn't just about your GPA and SAT numbers, and participating in extra-curricular activities can help.
A milder example; Doris Walker (Maureen O'Hara) in Miracle on 34th Street didn't expose her daughter to fairy tales, believing that she should be truthful with her child. While her decision in this regard was informed by her backstory, she was never cruel to her daughter, just pragmatic.
Robert, the little girl's father in Enchanted has a similar attitude; he discourages his daughter's interest in fairy tales by playing up the heroic achievements of real women such as Eleanor Roosevelt and Harriet Tubman. Even with his disillusionment about "happily ever after", Robert's ideas actually make sense for raising a girl in these days.
A Little Princess: as in the book, the power of storytlling is a major theme, but Miss. Minchin's opposition to it is all the more pronounced in the film. In the book she flatters all of Sara's tendencies, including her imagination, until the girl falls from grace. In the film, she is outraged from the start at Sara's flights of fancy and just gets all the more enraged when she finds that Sara's imagination has survived the reversal of fortune. Minchin believes in the girls learning to be 'productive and useful' where the story shows how Sara's imagination is her last and best weapon against degredation and despair.
Mama Boucher in The Waterboy ("You playin' the foosball behind my back Bobby Boucher?!!")
Dangerous Minds: One student's mother pulls him out of high school because he's being taught poetry, when she needs him to get a job to support the family.

Literature

Many a heroine of a Pony Tale was saddled (no pun intended) with parents like these, when they weren't obstructive in some other way to her dream of becoming an equestrian.
In Born To Run (book one of Mercedes Lackey's SERRAted Edge novels), one character ran away from home because her parents were like this.
In the Earthsea Trilogy, Ged's father, a blacksmith, is always telling him his fantasies will do him no good, and that learning to make a living as a blacksmith is the only realistic way for Ged to get by in the world. He's proven wrong when Ged becomes a wizard.
Thomas Gradgrind in Charles Dickens' Hard Times. He's got a utilitarian's love of Fact, and regards poetry and fiction as "destructive nonsense". His views have bad consequences for his daughter Louisa, who represses her emotions and enters a loveless marriage with her father's business associate.
The Dursleys throughout Harry Potter, especially Uncle Vernon. He very specifically tried to crush the potential for magic out of Harry with all sorts of means.
- Aunt Petunia also had a much more personal reason than just Vernon's dislike of magic: she had been insanely jealous of her sister for being magical while she had not been, and in a fit of pique upon learning that Petunia had written to Dumbledore and begged to be allowed to go to Hogwarts as well, she basically snapped and from that point on considered Lily Potter (nee Evans) a freak. Seeing her nephew around and having the same potential for her sister's magical power didn't help matters when he was dropped on their doorstep. It was probably the biggest reason why she had no objections to treating Harry like a slave. It was a kind of vicarious revenge against her sister for being 'special' while she wasn't. The idea of her son, who she absolutely adores despite being utterly blind to the idea that he could be a bully— which he indeed becomes over years of being a pampered and spoiler brat— being 'second fiddle' to Harry is anathema to her. Vernon probably had very little trouble trying to convince her that trying to make Harry as downtrodden as possible was the best thing to do to possibly, as he puts it, 'squash the magic out of him' and 'turn him normal'.
Matilda: Matilda's parents not only don't understand her love of reading over watching brainless gameshows and soap operas all day. Her father even goes as far to rip to pieces a library book she'd borrowed in front of her. Then there is the scene where her mother explains to her teacher Miss Honey why she thinks being pretty is more important than education. They much prefer her brother who is being trained to take over his father's used car place.
Michael's father in the Knight and Rogue Series does not approve of his youngest son going off and playing Knight Errant. His first major attempt to force Michael to quit is to legally require him to become a steward, and when Michael still refuses he has his son branded as a criminal and stripped of legal rights to try and eliminate all options other than being steward.
Yanus, Menolly's father in the Harper Hall Trilogy of Dragonriders of Pern was this way. Because centuries-old cultural tradition held that women could not become Harpers, Menolly's musical talent inconvenienced and embarrassed him. She disgraced him and his Hold simply by existing. He once beat her with a belt across her back for playing one measure of her own creation when she was supposed to be playing a traditional ballad.
Anais Nin recounts a Real Life example of a fantasy-forbidding mom in "The All-Seeing". Writing about a friend, possibly the occultist Jean Carteret, Anais talks about his collections of exotic objects, then says:

A violin hung on his wall. His violin nailed to the wall and never touched since the day his mother had said to him: "So you failed to get the prize you struggled for? You're hurt, you're humiliated, but I'm happy. Now you will stop playing the violin and wasting your life. You will be a man like your father, not a fiddler. I'm very glad you did not win the prize. You would have gone to Paris to study and become a good-for-nothing. We never had musicians in our family." With one phrase she had destroyed his first passion. He hung his violin on the wall. The strings snapped gradually and hung dead... He is condemned to wander outside of his violin, yet in every object around him I could place my ear and hear the music his mother was unable to silence."

Dean Koontz has a rather tragic variation: "The Twilight Before The Dawn" features a severely atheist father determined to raise his son with the same views. The man's wife dies and the young son begins trying to pray, to his father's angry frustration. When the little boy gets cancer and then dies the father still refuses to accept the boy's hope and faith until far later.
A Little Princess: not Sara Crewe's father who is delighted with, and encouraging of, Sara's flights of imagination, but her headmistress and de facto guardian Miss. Minchin. Sara retains her storytelling and imaginative ability throughtout her hardships and it is this ability that equips her to prevail.

Music

Grandpa in "Peter and the Wolf".

Tabletop RPG

A typical villain in Changeling: The Dreaming is a muggle who might mean well but his attitude makes him Walking Wasteland to fey creatures.

Live Action TV

Smallville: The end of the Pilot Movie sets up the Monster of the Week for the next episode, a teenager who's really into bugs - collecting, classifying, etc. A budding entymologist. His mother dislikes his hobby, partially on the grounds that he can't make a living at it.
Mike Chang's father on Glee. They temporarily disown each other when Mike refuses to quit the school musical.

Video Games

World of Warcraft's King Varian Wrynn is this regarding his son's class choice, wanting him to be a warrior like he is rather than the priest Anduin wants to be. At one point in the novel Wolfheart we literally see him thinking about how he needs to start discouraging his son from spending so much time with their religion, which is "obviously a bad influence".
Dragon Quest VII's King Burns regards his son Kiefer as an irresponsible Upper Class Twit chasing foolish dreams of adventure without any concept of the inherit risks. Even after Kiefer and his friends stumble across a way to restore the lands lost long ago in the war with the Demonlord, he forbids him from continuing (and attempts to stop the others as well).
Inazuma Eleven surprisingly has Gouenji's father disapprove of his playing soccer. The sport can't save lives, so apparently it doesn't mean anything compared to becoming a doctor.
Bianca's father in Pokémon Black and White is this until Elesa sets him straight.

Western Animation

ThunderCats (2011) has Claudus feel this way towards Lion-O's fascination with mythical technology in Thundera's world of Medieval Stasis. Of course, it comes in very handy once it's revealed that there are pockets of Lost Technology in the outside, and the Big Bad is invading with it.
The antagonist of Tinker Bell & The Great Fairy Rescue is Lizzy's father, an overly skeptical scientist who gives her grief for her 'flights of fancy'. When he learns she's filled her journal with everything she's learned about fairies, he starts ripping down all her pictures and throwing everything all, claiming it's 'high time she grows up'. Because being nine years old clearly equals adulthood.
This is a recurring trend on King of the Hill, where Hank's reaction to whatever Bobby's current interest is varies somewhere between annoyance, shame, and outrage. How extreme of a Fantasy-Forbidding Father Hank is varies from episode to episode; sometimes it's just a quick sigh for the audience's amusement and sometimes it's trying to urge Bobby to stop. But when Hank is being particularly close-minded and shaming of whatever Bobby's into that week, he'll usually learn to appreciate his son and the two of them will share a tender moment. One episode took this literally when Bobby began to get absorbed by a Fantasy book series in the B-Plot and Hank repeatedly told him to stop reading it in favor of a typical Boy's Adventure book.