In enzymology, a trans-2-enoyl-CoA reductase (NAD+) () is an enzyme that catalyzes the chemical reaction
Thus, the three substrates of this enzyme are trans-didehydroacyl-CoA, NADH, and H<sup>+</sup>, whereas its two products are acyl-CoA and NAD<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 acyl-CoA:NAD+ trans-2-oxidoreductase. This enzyme is also called trans-2-enoyl-CoA reductase (NAD+). This enzyme participates in butanoate metabolism.