In enzymology, a linoleate 11-lipoxygenase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are linoleate and O<sub>2</sub>, whereas its product is (9Z,12Z)-(11S)-11-hydroperoxyoctadeca-9,12-dienoate.
This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O<sub>2</sub> as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O<sub>2</sub>. The systematic name of this enzyme class is linoleate:oxygen 11S-oxidoreductase. This enzyme is also called linoleate dioxygenase, manganese lipoxygenase. This enzyme participates in linoleic acid metabolism.