In enzymology, a pyrroline-2-carboxylate reductase (EC 1.5.1.1) is an enzyme that catalyzes the chemical reaction

L-proline + NAD(P)+ ${\displaystyle \rightleftharpoons }$ 1-pyrroline-2-carboxylate + NAD(P)H + H⁺

The 3 substrates of this enzyme are L-proline, NAD⁺, and NADP⁺, whereas its 4 products are 1-pyrroline-2-carboxylate, NADH, NADPH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-proline:NAD(P)+ 2-oxidoreductase. This enzyme is also called Delta1-pyrroline-2-carboxylate reductase. This enzyme participates in lysine degradation and arginine and proline metabolism.