Anthranilate 3-monooxygenase (FAD) (, anthranilate 3-hydroxylase, anthranilate hydroxylase) is an enzyme with systematic name anthranilate,FAD:oxygen oxidoreductase (3-hydroxylating). This enzyme catalyses the following chemical reaction
The three substrates of this enzyme are anthranilic acid, reduced flavin adenine dinucleotide (FADH<sub>2</sub>), and oxygen. It products are 3-hydroxyanthranilic acid, FAD, and water. The bacterial enzyme from Geobacillus thermodenitrificans participates in tryptophan degradation.