In enzymology, a nitroalkane oxidase () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are nitroalkane, H<sub>2</sub>O, and O<sub>2</sub>, whereas its 4 products are aldehyde, ketone, nitrite, and H<sub>2</sub>O<sub>2</sub>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on other nitrogenous compounds as donors with oxygen as acceptor. The systematic name of this enzyme class is nitroalkane:oxygen oxidoreductase. Other names in common use include nitroethane oxidase, NAO, and nitroethane:oxygen oxidoreductase. This enzyme participates in nitrogen metabolism.