Peaceful, idyllic societies have a tendency to be vegetarian (if not vegan) in fiction. As often as not, these societies are portrayed as being morally, perhaps even spiritually/magically superior to our own, implying that humanity's meat-eating habit is somehow holding us back from living in a world of Crystal Spires and Togas. Sometimes it can be downright Anvilicious.
Some cases aren't so focused on the evils of eating animals so much as how circumstances might force people to adopt a vegetarian diet. See Future Food Is Artificial for examples of this.
Races that refrain from meat-eating simply because their digestive physiology is herbivorous aren't necessarily examples of this trope — if they have to eat plants, they're not really demonstrating moral superiority by doing so — but such species may subvert this trope's expectations if they're violently aggressive in spite of their diet.
Probably stems from the issues raised by Carnivore Confusion and Let's Meet the Meat. See also Mary Suetopia and Perfect Pacifist People. See Herbivores Are Friendly for the herbivorous animal equivalent.
- In Soul Hunter, Sennin have powers normal humans can only dream off and live in a floating, hi-tech mountain range in the sky. Because they use up less energy than normal people, they can subsist exclusively on fruits and vegetables, while eating meat or fish is forbidden. Likewise, the people of Tosenkyo (an isolated utopia country created by one of the Three Great Sennins) seemingly follow the same dietary conditions and stritc morals, only breeding sheep for wool. By contrast, Monster Sennin tend to be far more amoral and have no qualms about eating meat (or flesh).
- Wonder Woman (1987): Later issues present the Amazons as enlightened scholars like they were in their first iteration, and adds in their being vegetarians.
- In Logan's Run (at least the movie), it seems the characters are vegan: when faced with the concept that humans once raised animals for food, Jessica remarks that "it must have been a savage world". Of course, what they don't know is that their own food source died out years ago and they've been eating frozen people for decades.
- In Carnage Swallowing The Past the current generation is vegan from birth and eating meat and dairy is horrifying for them. They are also oblivious that not long ago people ate animal products. It seems that times are peaceful and people are generally very open to themselves. But it isn't equally for everyone as most of older generations struggle with their "carnist" past and they are going to therapies (similar of AA) to fight with their immense guilt.
- Technology similar to the uterine replicators in Lois McMaster Bujold's Vorkosigan Saga allows people to create "vat protein" with no animals being harmed. No one is a true vegan, but when forced to eat meat from a real animal, Cordelia is distinctly uncomfortable (Outside of one time when she'd been forced on a diet of oatmeal and salad dressing for several days for lack of any alternative). How "vegan" this situation is proves debatable in Ethan of Athos, where the reader is shown just where the protein in those vats comes from when the characters use the animal protein reclamation system to covertly dispose of a dead body.
- In Samuel R. Delany's Stars in My Pocket Like Grains of Sand, the enlightened human narrator is shocked at the idea of eating meat from what had been a living animal... being much more comfortable eating vat-grown human flesh.
- Subverted with the Galactic Federation from John Ringo's Legacy of the Aldenata, who are all not so much vegetarians as outright herbivores, and are in fact incapable of killing a living animal (a major plot point). The Darhel, one of the four races that make it up, are very obviously naturally carnivorous, with sharp, needle-like teeth. All of them are technologically far more advanced, claim moral superiority, except the Darhel have had a 5000 year long stranglehold on GalFed politics and economy, treat the most populous member race as slaves, and, since shortly after contact with humans was made, have been systematically sabotaging human attempts to fight off the omnivorous alien hordes in order to keep our numbers down or exterminate us altogether.
- From Animorphs:
- The Andalites turn out to be a subversion. They evolved to be herbivores and are initially disgusted at the idea of eating flesh, and, while not pacifists, they are portrayed as a heroic race fighting to defend the galaxy from the evil Yeerks. But those on Earth seem to not have any moral qualms about eating meat, especially since in human form they are rather overwhelmed by taste and try to eat anything. Also, it becomes increasingly clear over the course of the series that they're not as morally pure as they first appear.
- Before the Yeerks enslaved them, the Hork Bajir were stone age herbivores with no concept of war. They eventually do learn to defend themselves, but remain among the more unambiguously good characters in the series.
- Many Fairies in Artemis Fowl are vegetarians, and, if their society is not a utopia, they certainly think it is better than human civilization. Objectively it is not so different from human civilization. Some fairies are dim-witted, some are noble, some shallow, and some treacherous.
- The Star Wars Expanded Universe has Ithorians, a.k.a. "hammerheads". They're pacifists who don't eat meat and tend to sentient trees.
- Anne McCaffrey's Dinosaur Planet and Planet Pirates subvert the trope. Vegetarianism is legally mandated by The Federation, to such a strict degree that omnivorous species must unanimously swear off meat or be kicked out of the FSP. "Reversion" to hunting for meat is portrayed as a heinous crime, and leads to mutiny when the heavyworlders indulge in this forbidden practice. In the continuation, a major conflict is that while the majority culture of the Federation considers vegetarianism to be the only civilized diet, the heavyworlders reject this, since meat-eating and cannibalism were the only way that their genetically-engineered bodies could get enough nutrition to survive their first winter on their colony, and they're not too keen on being called barbarians by people who would never go through the same tribulations.
- S.L. Viehl's Joreniansdespite being pastoralists descended from predatorsare vegetarians (although Xonea Torin tries shrimp alfredo with scarcely a comment in Beyond Varallan). Zigzagged in that they're portrayed as both a Superior Species (if mainly because Terrans are rabid xenophobes and hypocrites in the Stardoc-verse) and a Proud Warrior Race (albeit one wearing the Cultured Warrior hat).
- Subverted in The Book of Dreams, which describes a world in which a colony of fanatical human vegetarians degenerates into mindless grazing animals.
- The gnomes of the idyllic society of Gnomes don't eat meat, probably because they also speak fluent animal, though they do consume songbird eggs and also dairy products if given by others.
- Subverted in Myth-Ion Improbable, in which the human inhabitants of Kowtow eat only vegetables and drink carrot juice, despite having vast herds of cattle that their cowboys look after. This is because the humans lost a war with vampires, who drained every other species except humans and horses into extinction and were about to exhaust the supply of those, too. So their leader put a spell on the entire planet, turning the vampires into ordinary cows except for the monthly "roundup", when they feed on the spell-docile humans, who then have a month off to regain their strength. There's only one non-vegan human on the planet, and he's a pampered prisoner who eats horse steaks.
- In A Song of Ice and Fire, the people of Naath are extreme pacifists who don't eat meat and mainly live on fruit.
- Star Trek
- Vulcans — which serve as the "morally-superior" race, at least in their own minds. However there are plants, and then there are Vulcan plants. In a Star Trek novel set on Spock's homeworld, the characters are attacked by a mobile, shrieking, prey-stalking carnivorous plant native to the region... and after it's been phasered to death, Spock eats some of it. One of the early TOS novels postulated that Vulcans were vegetarians partly because the herbivores previously used as meat died off during Surak's time. The most common reason given for their vegetarianism is the same one that led them to pacifism. They are such a violent and destructive race that they have to go to extreme lengths to not destroy themselves/conquer the universe/destroy the universe.
- Veganism seems common on Federation ships due to access to replicators that can create very convincing meat substitutes, avoiding the need to keep the real stuff in storage on long voyages. Attitudes about veganism vary widely, from disdain toward the concept of eating meat - like Riker claiming they don't enslave animals for food anymore, to acceptance - like Picard importing genuine seafood at what was implied to be great expense to eagerness: Dax and other patrons of Klingon cuisine complaining that their gagh is too dead.
- Along vaguely similar lines, eating meat (or at least beef) is illegal in the near-future world of seaQuest DSV, it seems, because the ecologically-minded folks of the late 2020s did not like the atmospheric implications of keeping large numbers of cows around. Real meat is available, though, and seems to hold a position and legality roughly akin to that of Cuban cigars in the U.S. today.
- Doctor Who: In the successful hippie commune of the Third Doctor serial "The Green Death", the local Marty Stu is on the hunt for a mushroom that tastes like meat, with the implication that it would eliminate the need for meat, and therefore meat-eating altogether.
- Inverted on Zoo: by the end of Season One, humans have given up on eating meat not because they care about animals, but because animals all over the world have gone kill-crazy towards human beings. Most livestock have either been destroyed or escaped, and even when meat is available, people are afraid it may be contaminated with whatever's affecting the animals.
- Many Christians believe that God originally intended for all creation to be vegetarian, and that this will be the ideal that would be perfected once the Kingdom is fulfilled. Indeed, in the Garden of Eden, God gave mankind the fruit of the trees to eat, and green plants to the animals. Later, in the Book of Isaiah, a vision of the New Earth states that carnivores would no longer eat other creatures, and that "the cow will feed with the bear, their young will lie down together, and the lion will eat straw like the ox." (Isaiah 11:7)
- The Elder Scrolls inverts this with the Bosmer (Wood Elves), who are religiously obliged to follow the "Green Pact" they made with their patron deity, Y'ffre, the God of the Forest, leading to them having a highly carnivorous diet within their homeland of Valenwood in order to protect their sacred plants. Culturally, they are also obliged to eat their fallen enemies after killing them in battle as they are not allowed to rot within (and thus taint) Valenwood. Both of these restrictions appear to be heavily relaxed on Bosmer who live outside of Valenwood, however. Even within Valenwood, there is much Loophole Abuse. Using fallen deadwood and eating fruit that fell off of trees naturally is allowed. Mushrooms may also be eaten, as they do not count as plants.
- In Black & White: The simple, pacifistic villagers of the first game only farm grain, despite having sheep and cows on hand, and the player gains evil points for putting animals into the village store to be eaten.
- Parodied and subverted in Improbable Island: The cafe in Kittania is introduced by a server going on a spiel about using only locally-grown produce to produce their selection of vegetarian and vegan meals... the effect of which is rather marred by the lovingly-detailed dripping, bloody steak that's also on the menu. As the server admits when you point this out, Kittymorphs are still carnivores, and just because they try to "tread lightly on Mother Earth" doesn't mean they can actually completely give up meat.