In enzymology, a 2-alkenal reductase (EC 1.3.1.74) is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are n-alkanal, NAD+, and NADP+, whereas its 4 products are alk-2-enal, NADH, NADPH, and H+.

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 n-alkanal:NAD(P)+ 2-oxidoreductase.

Other names in common use include NAD(P)H-dependent alkenal/one oxidoreductase, and NADPH:2-alkenal alpha,beta-hydrogenase.

As of late 2007, three structures have been solved for this class of enzymes, with PDB accession codes 2DM6, 2J3J, and 2J3K.