In enzymology, a NADPH peroxidase () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are NADPH, H<sup>+</sup>, and H<sub>2</sub>O<sub>2</sub>, whereas its two products are NADP<sup>+</sup> 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 NADPH:hydrogen-peroxide oxidoreductase. Other names in common use include TPNH peroxidase, NADP peroxidase, nicotinamide adenine dinucleotide phosphate peroxidase, TPN peroxidase, triphosphopyridine nucleotide peroxidase, and NADPH2 peroxidase.