Asiago (pronounced /ɑːsiˈɑːɡoʊ/) is an Italian cheese that can assume different textures, according to its aging, from smooth for the fresh Asiago (Asiago Pressato) to a crumbly texture for the aged cheese (Asiago d'allevo) of which the flavour is reminiscent of Parmesan. The aged cheese is often grated in salads, soups, pastas, and sauces while the fresh Asiago is sliced to prepare panini or sandwiches; it can also be melted on a variety of dishes. Asiago is treated as interchangeable with the parmesan and romano cheeses in some cuisines.

As Asiago has a protected designation of origin (Denominazione di Origine Protetta or DOP, see below), the only "official" Asiago is produced in the alpine area of the town of Asiago, province of Vicenza, in the Veneto region, and now is also made in the Alpine region of the Province of Trento, which has become part of the DOP area for Asiago production. Most Asiago, however, is made elsewhere using techniques and cultures that produce a cheese of the same or similar flavour.

Asiago is produced in co-ops, specialized groups of local dairies which provide high-quality grassfed cow's milk. Alpine milk is what makes Asiago a special, healthy cheese. Alpine meadows have a larger variety of grass species, medicinal plants and flowers all of which contribute to a better tasting milk with a higher protein content.

Asiago cheese is an Italian D.O.P. product (Denominazione di Origine Protetta), equivalent to a Protected Designation of Origin (PDO). This simply means that the product can be considered as real by European law if and only if it is produced in its specific origin area, and according to a specific regime, known as the Disciplinare di produzione. The EU law does not necessarily apply outside the European Union. Previously it had enjoyed protected status in a number of European countries with which Italy had bilateral agreements under the Denominazione d’Origine awarded by the presidential decree of 21 December 1978 and subsequently modified by the prime-ministerial decree of 1993-08-03, and by the ministerial decree of 1995-06-06 under which the current Disciplinare came into force.

Fresh Asiago is tender and can be used in the preparation of sandwiches and panini or as a table cheese. Aged Asiago can be used for grating and as a table cheese. The aged Asiago can be granular, like Parmesan or aged Gouda, and can feature a bit of a crunch due to a buildup of Tyrosine, an amino acid found in milk that crystallizes over time in aged cheeses. The more Tyrosine found in milk the higher quality the milk and a considerable amount has to be present for it to crystallize; therefore a crystallin texture is considered a sign of high quality in aged cheese. Aged Asiago features a very concentrated, complex variety of flavors ranging from the fruity, to the nutty, to the pungent. Some wheels can even taste a little like toasted bread.

This cheese is available in flavours ranging from fresh to mild to aged, and the types are described by their flavour. Dolce describes a mildly spicy asiago, several months old; medio describes a stronger product, aged longer; and piccante asiago is a hard, aged cheese with a piquant flavor, suitable for grating. Piccante asiago is also enjoyed as a flavorful table cheese, eaten in paper-thin slices.

Asiago d’Allevo is the mature, hard cheese. It is produced from skimmed raw cows’ milk and sold in flat cheese wheels weighing 8 to 14 kg (18 to 31 pounds). It is marketed as fresh (fresco) asiago, aged two to three months, good for sandwiches and salads, and medium-ripe (mezzano), aged four to five months. Slow-ripened (vecchio) asiago, aged nine months or longer, is a table cheese, also suitable for cooking.

Asiago is enjoyed as a complement to pasta, rice, pizza, or soup. It can also be served with hearty bread, salami, or such fruits as fresh figs or pears, and it goes well with a variety of beverages such as red wine, cranberry juice, and sparkling grape juice.