In enzymology, a NADPH peroxidase (EC 1.11.1.2) is an enzyme that catalyzes the chemical reaction

NADPH + H⁺ + H₂O₂ ${\displaystyle \rightleftharpoons }$ NADP⁺ + 2 H₂O

The 3 substrates of this enzyme are NADPH, H⁺, and H₂O₂, whereas its two products are NADP⁺ and H₂O.

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.