A truly spectacular example (and equally marvellous send-up) is the kung fu dinner theatre sequence from Meet the Robinsons.
Ben 10: Race Against Time: Ben turns into Grey Matter and rigs a contraption to launch food at the bullies who were making fun of him.
National Lampoon's Animal House had Bluto start one in the Faber cafeteria.
In Valley Girl, Julie starts one by smashing a plate of guacamole in Tommy's face at the Valley High junior prom. Randy and Fred escalate things by pelting popcorn and other snacks at the crowd. Naturally, a full-scale food fight breaks out; Randy and Julie escape from the chaos and flee the prom in Tommy's rented limousine.
The cafeteria food fight in Max Keeble's Big Move, is started, not surprisingly, by the title character as part of The Plan to ruin the Principal's chances of getting promoted to Superintendent before he moves out of town.
Eddie's Million Dollar Cook-Off has two food fights. One ended up actually serving the plot. The fight happened in a Home Ec. class, and with all the foodstuffs randomly mixing, it somehow made a delicious sauce purely by coincidence. The protagonist, who by the way plays on the baseball team, ends up replicating this sauce to enter into a cooking contest so his Jerk Jock buddies can mock him for being a cook.
In The Parent Trap rip-off It Takes Two (starring Mary-Kate and Ashley Olsen) there's a food fight that was started when one of the twins tripped a boy carrying a bowl of macaroni to cover her escape. The bowl flies through the air (in Slow Motion) and lands on Steve Guttenberg's head. Kirsty Alley can't cover her laughing, and he flicks a tab of butter at her. She stands up, and declares "FOOD FIGHT!"
Comes up in Whip It. Iron Maven flicks a ketchupy chip at Babe Ruthless. Babe throws some banana cream at Maven. Maven dumps a chocolate shake on Babe's head. Hilarity Ensues. What is even more hilarious, is that this appears to be an actual eating establishment that they destroy with ketchup, mustard, etc. Presumably the poor owners are then left to clean up the mess, oh what innocent fun.
Smashley Simpson: FOOD FIGHT!
The Wild Thornberrys movie had one such scene when Eliza went to boarding school and where her simian friend Darwin followed her.
The Doctor Who book The Monsters Inside has one, started deliberately by Rose to create a distraction. Rose credits a former boyfriend with teaching her the proper technique for starting a Food Fight: apparently, there's an art to it.
In Twelve Sharp, a food fight breaks out at the bonds office when Joyce barges in looking for trouble while Stephanie, Connie, and Lula are eating lunch. It gets settled by new file clerk Melvin zapping Joyce with a stun gun.
One happens in Dinosaurs Ate My Homework. Notably, all of the participants are superevolved carnivorous dinosaurs, and it takes place in a verse where they are the equivalent to humanity. And, somehow, they are throwing such things as mashed potatoes, milk, and spaghetti.
In the episode "Bros Before Bros" of Happy Endings, Dave attempts to make peace with the owner of a rival food truck by giving him a sandwich and asking to talk it out. The Brazilian accepts and offers to talk later. As Brad walks away, he chucks the sandwich at Dave, and soon Dave and his friends are engaged in a huge foodfight with the Brazilian and his employees.
Brothers and Sisters features a food fight between Holly and Nora (since both women are probably in their late 50s/early 60s, this makes it one odd Cat Fight). The obligatory cream cake ends up in Holly's cleavage, since Nora wasn't a very good shot. Considering that the cake got mentioned frequently throughout the episode, it's a Chekhovs Gunge as well.
An early episode was named "Food Fight" and featured... well, two food fights.The first was caused by Bulk throwing a pie at the school's principal, and missing, hitting his partner, Skull, who says "food fight". The second food fight is the Power Rangers trying to stop Rita's Pudgy Pig from eating all of the Earth's food.
Another food fight breaks out in "Return of an Old Friend Part 2", after the parents are freed and returned to the Parents' Day party. A pie misfire by Bulk and Skull hits Jason's dad, which starts off a chain reaction of the parents throwing food at one another. Miss Appleby, after having taken a pie to the blouse, says to Principal Caplan, "Well, you know what they say. If you can't beat them... join them!" and pies him in the face, causing himto join in too.
In the Sorority Forever episode "Sluts will be Pigs", a food fight gets out of hand.
In Waterloo Road, pupil Janeece is left to supervise the school's "breakfast club" as Melissa Ryan has not fully got her head in gear after revising PSHE with Eddie. A food fight commences. Not only is she powerless to stop it- she eventually joins in. The head chef is not impressed.
In an episode of Mr. Show, an angel and a demon participate in a Nickelodeon-style food fight game show.
Wild And Crazy Kids also had one; originally intended to be a "camp kids vs. counselors" contest, it quickly turned into a free-for-all.
In an episode of I Love Lucy Lucy and Ethel had taken jobs at a chocolate factory and eventually Lucy and another woman start throwing chocolate at each other.
An episode of the current series of Let's Make a Deal featured a large pie as a Zonk; when it was revealed, Wayne Brady went down to the pie and pulled a real one out from behind it, with which he hit Jonathan Mangum. At the end of the Show Mangum got his revenge, at which point a curtain opened revealing an entire rack of pies, resulting in a pie fight among the entire cast.
Happens at the end of Community episode The Art of Discourse. It's made funnier by the list of college experiences that Abed has been trying to complete throughout the episode. He stops trying to set them up and says they have to happen organically, and right afterwards the food fight, which was on the list, breaks out.
A (probably incomplete) list of foodstuffs routinely thrown over the contestants in Dick & Dom in da Bungalow: tinned tomatoes, mushy peas, baked beans, tapioca, rice pudding, custard, chocolate custard, mashed potatoes, mango chutney, spaghetti hoops. Oh, and from time to time they might get put in a bowl and have the ingredients for some recipe added to them (flour, lard, eggs etc). As one of the hosts put it; "You'd still be finding dried bits in your hair until the next week's show."
It's happened several times on Glee, along with frequent slushies to the faces of unpopular students. (Why Principal Figgins still allows them to be sold at the school is a mystery.)
The Thick of It gives us Malcolm Tucker and Julius Nicholson getting involved in one of these. In a conference room. In Whitehall. Over government policy. "Have some fucking chow mein!"
One early MTV video, "It's Inevitable" by Charlie, is set in a pastry-bakery in which a truly epic pie fight takes place. As the camera pans out at the end, lead singer Terry Slesser and his lady, who are more or less completely clean, are standing atop a table in the middle of the room, watching everyone else nail each other.
Nerina Pallot's "Everybody's Gone to War" features customers in a supermarket using foodstuffs to wage war against each other.
Now Ernie dragged him from his van and beneath the blazing sun, They stood there face to face, and Ted went for his bun. But Ernie was too quick, things didn't go the way Ted planned, And a strawberry-flavoured yogurt sent it spinning from his hand.
Now Susie ran between them and tried to keep them apart, And Ernie, he pushed her aside and a rock cake caught him underneath his heart. And he looked up in pained surprise and the concrete hardened crust, Of a stale pork pie caught him in the eye and Ernie bit the dust.
At the end of the 1999 Thanksgiving Episode of Smackdown!, DeGeneration X were pulverising Shane McMahon in the ring with Vince McMahon standing helpless on the stage due to D-X's restraining-order shenanigans. His solution? To call down not only other wrestlers who had beef with D-X, but most of the midcard roster to get some revenge. Of course, this being a Thanksgiving episode, tables of food had been placed all around ringside...
In a 1999 episode of SmackDown, there was a triple threat women's hardcore match that went into the concession stand featuring Ivory, Luna Vachon and Jacqueline.
Dragon magazine #44 had a game called "Food Fight" which provided rules for staging one of these in a school cafeteria.
"Food Fight" was the title of the sample mini-adventure in early editions of the Shadowrun game rules. Subverted in that, while it's set in a convenience store and lots of food gets blown to bits or tossed around, the scenario assumes that everybody's shooting guns.
The 80's arcade game Charly Chuck's Food Fight in which the player, as Charly, had to eat an ice cream cone at the end of the stage before it completely melted. But four angry chefs wanted to stop you at any cost. There were finite piles of food that included pies and tomatoes, but some foods had special properties: Peas were like buckshot (they scattered if they didn't connect), bananas were like boomerangs, and hugh chunks of watermelon never ran out. You lost a life if the ice cream completely melted (you were out of time), you fell into one of many holes on the playing field, you got hit by something a chef threw at you, or worse, if a chef caught and touched you, in which case your eyes spun, you got an Oh Crap look on your face and the food magically homed in on YOU, burying you in a messy pile!
The Three Stooges videogame has the characters raising money for an orphanage. One dayjob minigame requires serving a large number of pies to three fussy customers, and you need to remain professional by not getting pie in your face.
Invoked in the video game Bart Simpson's Escape from Camp Deadly. Surprisingly, this was also one of the more lethal cases of the trope (Bart has to defend himself from the other campers by throwing various food items that are strongly implied to be at best unappealing and at worst completely inedible without getting caught [if he does get caught, he's forced to eat all of the food he currently has on his person], and the other campers throw, not food, but knives and forks at Bart).
Chakona Space has "Alternate Thursdays", which can happen any day of the week and normally involve pie or some other desert.
The first episode of RWBY's second volume has a truly impressive one. It starts with Nora throwing grapes for Yang to catch in her mouth but escalates to a tomato to the face after a particularly bad pun. Yang retaliates and it slowly builds up with larger fruit until Nora lobs a pie which hits Weiss instead of Yang. A quick scene change later and the rest of the student body is fleeing the now devastated dinner hall, and Team RWBY and Team JNPR get into a super powered brawl using foodstuffs instead of their normal weapons.
Chowder: In "A Taste of Marzipan," Mung Daal and Endive get into a fight over who makes the best dish that escalates into a military skirmish, complete with foxholes, civilian casualties (Gazpacho), and heavy artillery (Schnitzel jumps off a roof and lands on Endive's camp).
An entire episode of Codename: Kids Next Door involves this, as the title kids fight Grandma Stuffem and her mutant food items. To rock opera style musical numbers no less.
In an episode of Kim Possible, Ron starts one of these in the school cafeteria; it's the first sign that all of Dr. Drakken's evil has been accidentally pumped into his brain.
An entire episode of Recess. A hidden culprit started a food fight. Gus was the only eyewitness but his friends warn him not to break the code by telling Miss Finster who started the food fight. It was Randall who started the food fight, and it is hinted that he was squealed on by every single member of the student body to Finster besides Gus and his friends.
In Ed Eddn Eddy's Valentine's Day special, Ed and Eddy and Lee and Marie start a food fight over Edd and May.
Eddy: *chucks a sandwich at Lee* Tell your stupid SISTER to stay away from our FRIEND!
Lee: *chucks two hotdogs at Eddy* Tell your stupid FRIEND to stay away from our SISTER!
In the intro for El Tigre, Manny and Frida start one of these. They subsequently sent to detention.
In The Proud Family, two food fights occurred in the episode where BB and CC got baptised. The first was when the two families were dining at the Red Clam (they were dining there because Samo and his brother ended up eating all the food on the table while the families were in prayer), where, after the seafood came down on the dining family (apparently this happens a lot in that restaurant), the two families (the Prouds, and Trudy's family) ended up having a huge food fight, while the families were bitter towards each other. Penny and Trudy attempted to stop them. The second time was at the end, where Samo and his brother inadvertently caused it when fighting over mashed potatoes. This time, it was a bit more friendly in nature.
In the Fairly OddParents movie Abra-Catastrophe, Timmy instigates one in his school cafeteria to keep Crocker from finding a Rule-free wish-granting muffin. and since it's Muffin Monday, the result is hundreds of muffins flying everywhere. And one muffler, but that's neither here nor there.
In the first episode of Ultimate Spider-Man, some villains break into the school and demand that Spider-Man give himself up. Pete promptly calls a food fight and sneaks away while it's taking place.
The 1955 Popeye cartoon "Cooking With Gags" has Popeye and Bluto trying to lure Wimpy into each's competing diner. It climaxes with the two adversaries hurling food and diner furniture at each other, which Wimpy uses to set himself up with a chair, table, and all the fixings for a full course dinner.
The Hair Bear Bunch episode "Goldilocks and the Three Bears'' had the bears and Mr. Peevly appearing in a modernized filming of the fairy tale. A flubbed line results in bowls of porridge hurled at one another.
Bogus starts one of these in the second act of the episode "Class Clown Bogus" as a tactic to stop a mean bully from bullying the other kids in the cafeteria.
This shows up at the beginning of the episode "Bogus To The Rescue". After Baddus and his Meteor Goons chase away the patrons of a restaurant in Bogusland, they start throwing food at each other, until the scene ends with a slice of cherry pie thrown at the screen.
Subverted in a PSA about nutrition: several junior high school students are seen grabbing fruits and vegetables and fondling them as if getting ready to throw them, interspersed with title cards: "Ready. Aim. Chew." And instead of throwing the food, they eat it, because their "food fight" is against poor eating habits.