2-deoxy-D-gluconate 3-dehydrogenase (EC 1.1.1.125) is an enzyme that catalyzes the chemical reaction

2-deoxy-D-gluconate + NAD⁺ ${\displaystyle \rightleftharpoons }$ 3-dehydro-2-deoxy-D-gluconate + NADH + H⁺

Thus, the two substrates of this enzyme are 2-deoxy-D-gluconate and NAD⁺, whereas its 3 products are 3-dehydro-2-deoxy-D-gluconate, 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 2-deoxy-D-gluconate:NAD⁺ 3-oxidoreductase. This enzyme is also called 2-deoxygluconate dehydrogenase. This enzyme participates in pentose and glucuronate interconversions.

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 1X1E.