Acetylindoxyl oxidase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are N-acetylindoxyl and oxygen, whereas its product is N-acetylisatin.
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 N-acetylindoxyl:oxygen oxidoreductase. This enzyme participates in tryptophan metabolism.