Buffalo mozzarella (Italian: mozzarella di bufala; Neapolitan: muzzarella 'e vufera) is a mozzarella made from the milk of the Italian Mediterranean buffalo. It is a dairy product traditionally manufactured in Campania, especially in the provinces of Caserta and Salerno.

Since 1996, mozzarella di bufala campana is also registered as an EU and UK protected designation of origin (PDO) product. The protected origin appellation requires that it may only be produced with a traditional recipe in select locations in the regions of Campania, Lazio, Apulia, and Molise.

In Italy, the cheese is produced nationwide using Italian Mediterranean buffalo milk under the government's official name mozzarella di latte di bufala because Italian buffalo are found in all Italian regions. Only the specific type of mozzarella di bufala campana PDO is produced in the area reaching from Rome, Lazio, to Paestum, near Salerno, Campania, and there are also production areas in the province of Foggia, Apulia, and in Venafro, Molise. Buffalo mozzarella is a €300m ($330m) per year industry in Italy, which produces around 33,000 tonnes of it every year, with 16 percent sold abroad (mostly in the European Union). France and Germany are the main importers, but sales to Japan and Russia are growing.

Apart from in Italy, its birthplace, buffalo mozzarella is manufactured in many other countries around the world. There are producers in Switzerland, the United States, Australia, Mexico, Brazil, Canada, China, Japan, Venezuela, Argentina, the United Kingdom, Ireland, Spain, Sweden, Colombia, Thailand, Israel, Egypt, India, and South Africa, all using milk from their own herds of water buffaloes.

Buffalo mozzarella from Campania bears the trademark mozzarella di bufala campana. In 1993, it was granted denominazione di origine controllata (DOC) status, in 1996 the trademark received the registry number 1107/96, and in 2008 the European Union granted protected geographical status and the PDO designation. The Consorzio per la Tutela del Formaggio di Bufala Campana (lit. 'Consortium for the Protection of the Buffalo Cheese of Campania') is an organization of approximately 200 producers that, under Italian law, is responsible for the "protection, surveillance, promotion and marketing" of mozzarella di bufala campana. The mozzarella industry in Italy resulted from 34,990 recorded females of the Italian Mediterranean breed, which account for ≈30% of the total dairy buffalo population (this percentage does not exist in any other country) and have a mean production of 2,356 kg milk in 270 days of lactation, with 8% fat, and 4.63% protein.

The history of water buffalo in Italy is not settled. One theory is that Asian water buffalo were brought to Italy by Goths during the migrations of the early medieval period. However, according to the Consorzio per la Tutela del Formaggio Mozzarella di Bufala Campana, the "most likely hypothesis" is that they were introduced by Normans from Sicily in 1000, and that Arabs had introduced them into Sicily. The Consorzio per la Tutela also refers to fossil evidence (the prehistoric European Water Buffalo, Bubalus murrensis) suggesting that water buffalo may have originated in Italy. A fourth theory is that water buffalo were brought from Mesopotamia into the Near East by Arabs and then introduced into Europe by pilgrims and returning crusaders.

"In ancient times, the buffalo was a familiar sight in the countryside, since it was widely used as a draught animal in ploughing compact and watery terrains, both because of its strength and the size of its hooves, which do not sink too deeply into moist soils."

References to cheese products made from water buffalo milk appeared for the first time at the beginning of the 12th century. Buffalo mozzarella became widespread throughout the south of Italy from the second half of the 18th century, before which it had been produced only in small quantities.