Tocopherols (or TCP) are a class of chemical compounds of which many have vitamin E activity. It is a series of organic compounds consisting of various methylated phenols. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was given the name "tocopherol" from the Greek words "τόκος" [birth], and "φέρειν", [to bear or carry] meaning in sum "to carry a pregnancy," with the ending "-ol" signifying its status as a chemical alcohol.

alpha-Tocopherol is the main source found in supplements and in the European diet, where the main dietary sources are olive and sunflower oils, while gamma-tocopherol is the most common form in the American diet due to a higher intake of soybean and corn oil.,

Tocotrienols, which are related compounds, also have vitamin E activity. All of these various derivatives with vitamin activity may correctly be referred to as "vitamin E." Tocopherols and tocotrienols are fat-soluble antioxidants but also seem to have many other functions in the body.