Sheep's milk is the milk of domestic sheep. It is commonly used to make cultured dairy products, such as cheese. Some of the most popular sheep cheeses include feta (Greece), ricotta (Italy), Roquefort (France) and Oscypek (Poland).

Milk is a white liquid food produced by the mammary glands of mammals and the caecilian Siphonops annulatus. It is the primary source of nutrition for young mammals before they are able to digest solid food. Immune factors and immune-modulating components in milk contribute to milk immunity. Early-lactation milk, which is called colostrum, contains antibodies that strengthen the immune system and thus reduce the risk of many diseases. Milk contains many nutrients, including calcium and protein, but also lactose and saturated fat.