Gorgonzola (Italian pronunciation: [ɡorɡonˈdzɔla]) is a veined Italian blue cheese, made from unskimmed cow's and/or goat's milk. It can be buttery or firm, crumbly and quite salty, with a 'bite' from its blue veining. It has been made since the early Middle Ages, but became marbled with greenish-blue mold only in the eleventh century. It is frequently used in Italian cooking. The name comes from Gorgonzola, a small town near Milan, Italy, where, it is reported, the cheese was first made in 879; however, this claim of geographical origin is disputed by other towns.

Gorgonzola is made in the regions of Piedmont and Lombardy from whole cow's milk, to which is added the bacteria Lactobacillus bulgaricus and Streptococcus thermophilus, along with spores of the mold Penicillium glaucum. Recently, Penicillium roqueforti has started to be used to make Gorgonzola, besides its use in Roquefort cheese. After the whey is removed, it is aged at low temperatures. During the aging process, metal rods are inserted and removed, creating air channels that allow the mold spores to germinate and cause the characteristic veining. Gorgonzola is typically aged for three to four months. The length of the aging process determines the consistency of the cheese. A firm Gorgonzola is aged longer than creamy Gorgonzola. The cheese is usually packaged and sold in a foil wrapper.

Gorgonzola may be consumed in many ways. It may be melted into a risotto in the final stage of cooking, for instance. Another fairly traditional dish sees gorgonzola served alongside polenta. Pasta with gorgonzola is a dish appreciated almost everywhere in Italy by gorgonzola lovers; usually gorgonzola goes on short pasta, such as penne, rigatoni, mezze maniche, or sedani, not with spaghetti or linguine. Because of its distinctive flavor, gorgonzola is frequently offered as a topping on pizza, alone or with other soft cheeses (this is the so-called pizza ai quattro formaggi).

Today, by law, the zone of production includes only a defined area. What was once the village of Gorgonzola (not far from Milan) is being swallowed up by suburbs. Most gorgonzola is actually produced in the province of Novara, but the DOC zone also includes such provinces as Bergamo, Brescia, Como, Cremona, Cuneo, Lecco, Lodi, Milan, Pavia, Varese, Verbano-Cusio-Ossola, and Vercelli, as well as a number of comunes in the area of Casale Monferrato (province of Alessandria).

Gorgonzola made with goat's milk is firm and salty. It is made usually in the Prealpi area of Piedmont and Lombardy, especially in the provinces Lecco and Alessandria.