Soybeans (US) or soya beans (UK) (Glycine max) are a high-protein legume (Family Fabaceae) grown as food for both humans and livestock. The word soy comes from Japanese shoyu.

Soybeans may be boiled whole (in the green pod) and served with salt, often under the Japanese name edamame. Soybeans prepared this way are a popular local snack in Hawai'i where, like in Japan and China, the bean and products made from the bean (miso, natto, tofu, douchi, etc.) are a significant part of the diet.

The beans can be processed in a variety of ways. Common forms of soy (or soya) include soy meal (often used as animal feed), soy flour, tofu, textured vegetable protein (TVP, which is made into a wide variety of vegetarian foods, some of them intended to imitate meat), tempeh, soy lecithin and vegetable oil. Soybeans are also the primary ingredient involved in the production of soy sauce (or shoyu).

Many traditional dairy products have been imitated using soybeans, and products such as soy milk, soy yoghurt and soy cream cheese are readily available in most supermarkets. These products have the same texture and appearance as milk-based ones, however regular soy milk does not contain significant amounts of calcium, since the high calcium content of soybeans is bound to the insoluble constituents and remains in the okara. Therefore, many manufacturers of soy milk sell calcium-enriched products as well. Tofu often contains high amounts of this important mineral since calcium salts are used to coagulate the protein in soy milk in order to produce tofu. Additionally, soy protein has been found to reduce renal excretion of calcium, an effect that is reinforced by soy products' high potassium content. Most soy products must not be fed to infants, although specially designed soy infant formula has also been made in recent times. This formula has extra vitamins and other nutrients added to it to make it compatible with the infant's needs. In some cases, infants fed normal adult soy milk on a long-term basis have become extremely malnourished and even died. In addition, soy allergies are one of the more common food allergies.

Soybeans are also used in industrial products including oils, soap, cosmetics, resins, plastics, inks, crayons, solvents, and biodiesel.

Soybeans are native to southeast Asia, but 45 percent of the world's soybean area, and 55 percent of production, is in the United States. The US produced 75 million metric tons of soybeans in 2000 of which more than one-third was exported. Other leading producers are Brazil, Argentina, China, and India. Much of the US production is either fed to animals or exported, though US consumption of soy by people has been increasing. Soy oil makes up 80% of the edible oil consumption in the U.S.

Soybeans are one of the crops that are being genetically modified, and GMO soybeans are being used in an increasing number of products. Currently, 80% of all soybeans cultivated for the commercial market are genetically modified. Monsanto is the world's leader in genetically modified soy for the commercial market.

Soybeans are considered a source of complete protein, i.e., protein that contains significant amounts of the essential amino acids that must be provided to the human body because of its inability to synthesize them.