1,2-dihydroxynaphthalene dioxygenase (, 1,2-DHN dioxygenase, DHNDO, 1,2-dihydroxynaphthalene oxygenase, 1,2-dihydroxynaphthalene:oxygen oxidoreductase) is an enzyme with systematic name naphthalene-1,2-diol:oxygen oxidoreductase. This enzyme catalyses the following chemical reaction
It is involved in naphthalene degradation in Pseudomonads.