In enzymology, a 4-hydroxy-tetrahydrodipicolinate reductase (EC 1.17.1.8) is an enzyme that catalyzes the chemical reaction The 3 substrates of this enzyme are (S)-2,3,4,5-tetrahydropyridine-2,6-dicarboxylate, NAD+ or NADP+, and H2O, whereas its 3 products are (2S,4S)-4-hydroxy-2,3,4,5-tetrahydrodipicolinate, NADH or NADPH, and H+.

This enzyme participates in lysine biosynthesis.

This enzyme belongs to the family of oxidoreductases, specifically those acting on CH or CH2 groups with NAD+ or NADP+ as acceptor.

The systematic name of this enzyme class is (S)-2,3,4,5-tetrahydropyridine-2,6-dicarboxylate:NAD(P)+ 4-oxidoreductase.

Other names in common use include: