vegetable oil Click to see full answer. Likewise, people ask, what oil does McDonald’s use for fries? Vegetable oil Also, what kind of oil does McDonalds cook with? vegetable oil Also, are McDonald’s fries cooked in peanut oil? Avoiding Nuts Most people with a peanut allergy are concerned about frying oil. McDonald’s says it uses a canola oil blend for deep frying. 2? “All products available at our restaurants may contain or come into contact with peanuts, tree nuts or other allergens,” McDonald’s said in a statement.Are McDonald’s french fries vegetarian?In fact, they contain beef fat. They are not vegetarian, which means they are also not vegan. Years ago, McDonald’s settled a lawsuit with some vegetarians, after leading people to believe their fries were vegetarian when they actually contained beef fat. Today, McDonald’s French Fries are not vegetarian.