Prosciutto (/prəˈʃuːtoʊ, proʊˈ-/ prə-SHOO-toh, proh-; Italian: [proʃˈʃutto]), also known as prosciutto crudo, is an uncooked, unsmoked, and dry-cured ham. It is usually served thinly sliced.

Several regions in Italy have their own variations of prosciutto crudo, each with degrees of protected status, but the most prized are Prosciutto di Parma DOP, from Emilia-Romagna, and Prosciutto di San Daniele DOP, from Friuli-Venezia Giulia. Unlike speck (Speck Alto Adige) from the South Tyrol region, prosciutto is not smoked. There is also a tradition of making prosciutto in southern Switzerland.

In Italian, prosciutto means any type of ham, either dry-cured (prosciutto crudo or simply crudo) or cooked (prosciutto cotto), but in English-speaking countries, it usually means either Italian prosciutto crudo or similar hams made elsewhere. However, the word prosciutto itself is not protected; cooked ham may legally be, and in practice is, sold as prosciutto (usually as prosciutto cotto, and from Italy or made in the Italian style) in English-speaking regions.

The word prosciutto derives in turn from Italian asciutto (lit. 'dry'), with prefix substitution, or from Vulgar Latin pro (before) + exsuctus (past participle of exsugere, 'to suck out [the moisture]'); the Portuguese presunto has the same etymology. It is similar to the modern Italian verb prosciugare ('to dry thoroughly'; from Latin pro + exsucare ('to extract the juices from')).

Prosciutto is made from either a pig's or a wild boar's hind leg or thigh, and the base term prosciutto specifically refers to this product. Prosciutto may also be made using the hind leg of other animals, in which case the name of the animal is included in the name of the product, for example prosciutto di agnello (lit. 'lamb ham'). The process of making prosciutto can take from nine months to two years, depending on the size of the ham.

A writer on Italian food, Bill Buford, describes talking to an old Italian butcher who says:

When I was young, there was one kind of prosciutto. It was made in the winter, by hand, and aged for two years. It was sweet when you smelled it. A profound perfume. Unmistakable. To age a prosciutto is a subtle business. If it's too warm, the aging process never begins. The meat spoils. If it's too dry, the meat is ruined. It needs to be damp but cool. The summer is too hot. In the winter—that's when you make salumi. Your prosciutto. Your soppressata. Your sausages.

Today, the ham is first cleaned, salted, and left for about two months. During this time, the ham is pressed gradually and carefully to drain all blood left in the meat without breaking the bone. Next, it is washed several times to remove the salt and is hung in a dark, well-ventilated environment. The surrounding air is important to the final quality of the ham; the best results are obtained in a cold climate. The ham is then left until dry. The time this takes varies, depending on the local climate and size of the ham. When the ham is completely dry, it is hung to air, either at room temperature or in a controlled environment, for up to 18 months.