Sago /ˈseɪɡoʊ/ is a starch extracted in the spongy center or pith, of various tropical palm stems, especially Metroxylon sagu. It is a major staple food for the lowland peoples of New Guinea and the Moluccas, where it is called saksak, rabia and sagu. A type of flour, called sago flour, is made from sago. The largest supply of sago comes from the East Indies. Large quantities of sago are sent to Europe and North America for cooking purposes. It is traditionally cooked and eaten in various forms, such as rolled into balls, mixed with boiling water to form a paste, or as a pancake. Sago is often produced commercially in the form of "pearls". Sago pearls can be boiled with water or milk and sugar to make a sweet sago pudding. Sago pearls are similar in appearance to tapioca pearls and the two may be used interchangeably in some dishes.

The name sago is also sometimes used for starch extracted from other sources, especially the sago cycad, Cycas revoluta. The sago cycad is also commonly known (confusingly) as the sago palm, although this is a misnomer as cycads are not palms. Extracting edible starch from the sago cycad requires special care due to the poisonous nature of cycads. Cycad sago is used for many of the same purposes as palm sago. In Sri Lanka it is known as sawu or sau and is used to prepare a porridge named sawu kanda.