In enzymology, a xanthommatin reductase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are 5,12-dihydroxanthommatin and NAD<sup>+</sup>, whereas its three products are xanthommatin, NADH, and H<sup>+</sup>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 5,12-dihydroxanthommatin:NAD+ oxidoreductase.