In enzymology, a Delta12-fatty acid dehydrogenase () is an enzyme that catalyzes the chemical reaction
where AH is either NADH or NADPH.
The 3 substrates of this enzyme are linoleate, 2AH, and O<sub>2</sub>, whereas its 3 products are crepenynate, 2A, and H<sub>2</sub>O.
This enzyme belongs to the family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derive from O miscellaneous.
This enzyme participates in linoleic acid metabolism.
The systematic name of this enzyme class is linoleate, hydrogen-donor:oxygen oxidoreductase (Delta12-unsaturating). Other names in common use include