Mayonnaise is not considered a dairy product, though it does have pasteurized eggs and oil in it. Those who consider themselves vegans will probably want to stay away from mayonnaise altogether because of the fact that it contains eggs which are in fact an animal by-product.

Those who are allergic to most dairy products will also probably want to limit the amount of mayonnaise they eat, especially if they experience a negative reaction from eating it. If you are able to eat mayonnaise without any problems whatsoever though, you can feel free to keep eating it without worrying at all.