In enzymology, a nicotinate dehydrogenase () is an enzyme that catalyzes the chemical reaction
<div align=center><small>nicotinate + H<sub>2</sub>O + NADP<sup>+</sup> 6-hydroxynicotinate + NADPH + H<sup>+</sup></small></div>
The 3 substrates of this enzyme are nicotinate, H<sub>2</sub>O, and NADP<sup>+</sup>, whereas its 3 products are 6-hydroxynicotinate, NADPH, and H<sup>+</sup>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH<sub>2</sub> groups with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor.
The systematic name of this enzyme class is nicotinate:NADP<sup>+</sup> 6-oxidoreductase (hydroxylating). Other names in common use include nicotinic acid hydroxylase, and nicotinate hydroxylase.
This enzyme participates in nicotinate and nicotinamide metabolism. It has 2 cofactors: FAD, and Iron.