In enzymology, a bromoxynil nitrilase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are 3,5-dibromo-4-hydroxybenzonitrile and H<sub>2</sub>O, whereas its two products are 3,5-dibromo-4-hydroxy-benzoate and NH<sub>3</sub>.
This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in nitriles. The systematic name of this enzyme class is 3,5-dibromo-4-hydroxybenzonitrile aminohydrolase. This enzyme participates in 1,4-dichlorobenzene degradation.