In enzymology, a 6-hydroxynicotinate dehydrogenase () is an enzyme that catalyzes the chemical reaction
The 3 substrates of this enzyme are 6-hydroxynicotinate, H<sub>2</sub>O, and O<sub>2</sub>, whereas its two products are 2,6-dihydroxynicotinate and H<sub>2</sub>O<sub>2</sub>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH<sub>2</sub> groups with oxygen as acceptor. The systematic name of this enzyme class is 6-hydroxynicotinate:O2 oxidoreductase. Other names in common use include 6-hydroxynicotinic acid hydroxylase, 6-hydroxynicotinic acid dehydrogenase, and 6-hydroxynicotinate hydroxylase.