In enzymology, a cyclohexane-1,2-diol dehydrogenase (EC 1.1.1.174) is an enzyme that catalyzes the chemical reaction

trans-cyclohexane-1,2-diol + NAD⁺ ${\displaystyle \rightleftharpoons }$ 2-hydroxycyclohexan-1-one + NADH + H⁺

Thus, the two substrates of this enzyme are trans-cyclohexane-1,2-diol and NAD⁺, whereas its 3 products are 2-hydroxycyclohexan-1-one, NADH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is trans-cyclohexane-1,2-diol:NAD⁺ 1-oxidoreductase. This enzyme participates in caprolactam degradation.