The simple answer is yes, Vegans and Vegetarians can and do eat Pizza. Both will need to use a different type of Mozzarella or other cheese but these are readily available both online and in larger grocery stores.
Pizzas should be perfect for vegetarians and vegans as the dough is 4 simple ingredients, flour, water, yeast and salt so there's no issue there. No problem with the tomato sauce, obviously and there's plenty of toppings that are ideal for both.
The problem comes from the cheese which is made from animal milk meaning it's no good for vegans but you'd think fine for vegetarians but that's not actually the case with mozzarella as it's made using animal rennet which is an enzyme produced in animals and therefore not vegetarian friendly either.
Vegetarian pizza isn't too dissimilar to regular pizza as vegetarians eat dairy so cheese isn't off the menu, the only problem for vegetarians is the animal rennet enzyme that's used to make Mozzarella. Luckily there's a plant based rennet substitute so if you are vegetarian or just making a pizza for someone that is simply check the packaging of your Mozzarella and make sure it's vegetarian friendly.
Making vegan pizza is slightly more complicated as vegans don't consume any dairy so cheese is out. Luckily there are cheese alternatives like MozzaRisella, which is available on Amazon here and Green Vie, also on Amazon here which you can simply substitute for Mozzarella and now your pizza is vegan friendly.
You can probably figure out for yourself that any meat based products are out for both vegans and veggies and vegetables are fine but there are some other toppings that aren't so clear cut. Take a look at the list of toppings below and you'll see if it's ok for vegans or veggies.
| Topping | Vegetarian | Vegan |
|---|---|---|
| Anchovy | No | No |
| Artichoke | Yes | Yes |
| Arugula / Rocket | Yes | Yes |
| Asparagus | Yes | Yes |
| Aubergine / Eggplant | Yes | Yes |
| Bacon | No | No |
| Basil | Yes | Yes |
| Bell Peppers | Yes | Yes |
| Broccoli | Yes | Yes |
| Chicken | No | No |
| Chickpeas | Yes | Yes |
| Chili Peppers | Yes | Yes |
| Dill | Yes | Yes |
| Fennel | Yes | Yes |
| Garlic | Yes | Yes |
| Ground Beef | No | No |
| Haloumi | Sometimes | No |
| Jalapeños | Yes | Yes |
| Mascarpone | Sometimes | No |
| Mushrooms | Yes | Yes |
| N'Duja | No | No |
| Olives / Olive Oil | Yes | Yes |
| Onion | Yes | Yes |
| Oregano | Yes | Yes |
| Parma Ham | No | No |
| Parsley | Yes | Yes |
| Pepperoni | No | No |
| Piquanté Peppers | Yes | Yes |
| Prosciutto | No | No |
| Ricotta | Sometimes | No |
| Salami | No | No |
| Sausage | No | No |
| Sweetcorn | Yes | Yes |
| Tomato | Yes | Yes |
| Zucchini / Courgette | Yes | Yes |
As you can see from the table above, other than meats and some cheeses there's not many of the popular toppings that vegetarians and vegans can't have on a pizza, and if you remember that there are vegetarian alternatives to things like sausage, chicken and ground beef then there's even less that can't be used.
