The quick answer to the question is that it depends on the movie theater chain you go to.
Classic movie theater popcorn is often butter-flavored, so you might think that means it contains dairy and is therefore not vegetarian-friendly. However, the butter flavor in movie theaters is almost always artificial, meaning it does not contain dairy.
There is some debate in the vegan community as to whether unknown artificial flavors (such as artificial butter flavoring) can be considered vegan-friendly, as they may contain trace amounts of animal products without the consumer knowing.
Whether you believe in artificial butter flavor or not, here are all the details about popcorn served at major movie theater chains.
AMC
AMC confirms in their allergen information that their regular popcorn contains no dairy or other non-vegan-friendly ingredients, except for butter. However, butter seasoning contains a small amount of milk in the form of butter.
The company says you can request no seasoning added to your popcorn. All popcorn is popped in the same area, so if you avoid dairy due to a severe allergy, you are advised to avoid this product.
If you don’t have allergies and don’t mind the amount of dairy, you can eat regular popcorn at AMC.
All of AMC’s specialty popcorn has non-vegan ingredients, such as their caramel corn and cheddar corn. Their specialty popcorn is not considered vegetarian-friendly.
Conclusion: Regular popcorn without butter is vegetarian-friendly.
Regal Cinema
Regal Cinemas only provided nutritional and allergen information via a company tweet in 2018. In this tweet, they said that all ingredients in their popcorn should be vegetarian-friendly, but a later tweet clarified that this varies from theater to theater.
Some people have reported that the butter topping used in some theaters contains dairy and is not vegetarian-friendly.
Conclusion: Check with your local theater about their nutritional and allergen information.
cinemamark
Cinemark says their popcorn salt “may contain dairy.” You can request that they pop your popcorn without salt.
If you avoid non-vegan ingredients due to a severe allergy, theaters recommend avoiding popcorn altogether. All popcorn is prepared in the same area and is subject to cross-contamination.
If you don’t have allergies and don’t mind the amount of dairy, you can choose unsalted or salted popcorn. Without salt, you can consume trace amounts of dairy from cross-contamination. If the popcorn is prepared with salt, you may be consuming trace amounts of dairy products present in the salt.
Cinemark has two different butter toppings. The first is a butter topping made with anhydrous butterfat and contains dairy. A second choice is a butter flavored topping, which does not contain dairy or other non-vegan ingredients.
Conclusion: Popcorn is regular popcorn without salt and either no topping or “butter flavored topping” is vegan-friendly.