In enzymology, a Delta1-piperideine-2-carboxylate reductase (EC 1.5.1.21) is an enzyme that catalyzes the chemical reaction

L-pipecolate + NADP⁺ ${\displaystyle \rightleftharpoons }$ Delta₁-piperideine-2-carboxylate + NADPH + H⁺

Thus, the two substrates of this enzyme are L-pipecolate and NADP⁺, whereas its 3 products are Delta1-piperideine-2-carboxylate, 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-pipecolate:NADP+ 2-oxidoreductase. Other names in common use include 1,2-didehydropipecolate reductase, P2C reductase, and 1,2-didehydropipecolic reductase. This enzyme participates in lysine degradation.