Butylated hydroxytoluene (BHT), also known as dibutylhydroxytoluene, is a lipophilic organic compound, chemically a derivative of phenol, that is useful for its antioxidant properties. European and U.S. regulations allow small amounts to be used as a food additive. In addition to this use, BHT is widely used to prevent oxidation in fluids (e.g. fuel, oil) and other materials where free radicals must be controlled.

Chemical formula : C15H24O

BHT is primarily used as an antioxidant food additive.. It is permitted in the European Union under E321. It is forbidden as food additive in Japan (since 1958), Romania, Sweden, and Australia Since the 1970s, BHT has been steadily replaced with BHA.

BHT is also used as an antioxidant in products such as cosmetics, pharmaceuticals, rubber, electrical transformer oil and industrial additive.