If vegetarian and vegan tourists take the time to conduct some preliminary research and preparation, Italy has the potential to be a wonderful vacation location for them.

Vegetarianism has a deep-rooted history in Roman culture and practises. Pythagoras, the famed Greek philosopher and vegetarian, influenced some Romans. Epicurus, who supported vegetarianism as part of a cruelty-free and pleasure-filled existence and from whom we got the term epicurean, also influenced some Romans. In particular, the Roman senator Seneca was a vegetarian. Additionally, Roman gladiators typically bulked up on vegetarian fare such as barley and beans in order to keep themselves plump due to the limited and lean portions of meat that they consumed.

Vegetarianism is an ancient practise that is still practised in Italy today. According to a study that was conducted in 2011, over 10% of Italians are vegetarian, making Italy the country in the European Union with the highest percentage of vegetarians. Although veganism is less widespread in countries where dairy products and eggs are often consumed, it is not impossible for vegans to enjoy a satisfying diet when vacationing in Italy.

The Italian food that is presented on menus in Italy is not the same as that which is served in the United States due to the following reasons:

Butter is not commonly used in Italian cooking, and many restaurants do not even keep it on hand in their kitchens. Olive oil is frequently recommended as a healthy alternative to other types of fat, which is beneficial for vegans.
At a same vein, cheese is not typically served on top of spaghetti unless in eateries that cater to tourists. In addition, it is not unusual for restaurants to offer cheeseless pizza or pizza marinara as an option on their menus.
On the majority of Italian menus, these sections are broken down as follows:
Antipasti (appetisers) (appetizers)
Primi piatti (first courses)
Secondi piatti (main courses)
Contorni (side items/vegetables)
Dolci (dessert) 
The vast majority of the starters and side dishes, known as primi piatti and contorni, will adhere to a vegetarian and/or vegan diet, whilst the secondi piatti will centre on meat dishes.
In spite of all of this, a significant number of traditional Italian meals actually do contain meat. The majority of broths used in soups are either beef or chicken based. Stuffed fritti misto, often known as mixed batter-fried meals, can be made with either beef or pork. Guanciale, also known as swine jowl that has been cured, is commonly used as a basis ingredient in a number of other sauces, such as pasta alla amatriciana and spaghetti alla carbonara. Desserts typically include a base of cream or eggs as their primary ingredient.
How to Place an Order
The majority of Italians are fluent in English. However, in order to err on the side of caution, it is essential to specify any dietary limitations you have.

The most essential point to keep in mind is that the word "vegetarian" does not have the same meaning in Italian as it does in English. This is true of the majority of European countries as well. If you tell the waiter that you are a vegetarian (in Italian, sono un vegetariano), he may serve you a soup or pasta dish that contains meat even though it is predominantly made of vegetables. For example, he may bring you a pasta dish that contains pancetta. In point of fact, many Italians who identify as vegetarians will gladly consume a dish that contains trace amounts of meat and will continue to identify as vegetarians despite having done so.

Instead, be careful to inquire about the following when you are placing an order for a dish:

E senza carne? - Does it not include any meat?
E senza formaggio? - Does it not include cheese?
E senza latte? - Does it not contain milk?
E senza uova? Does it not include any eggs?
If you want to order a dish that does not contain any of those items, all you need to do is name the dish and add the word "senza" before the restriction. For instance, if you want to order pasta with tomato sauce but without cheese, you should inquire about ordering pasta marinara senza formaggio from the waiter.