In enzymology, a fatty-acid peroxidase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are palmitate and H<sub>2</sub>O<sub>2</sub>, whereas its 3 products are pentadecanal, CO<sub>2</sub>, and H<sub>2</sub>O.
This enzyme belongs to the family of oxidoreductases, specifically those acting on a peroxide as acceptor (peroxidases). The systematic name of this enzyme class is hexadecanoate:hydrogen-peroxide oxidoreductase. This enzyme is also called long chain fatty acid peroxidase.