In enzymology, D-xylose 1-dehydrogenase (NADP<sup>+</sup>) () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are D-xylose and oxidised nicotinamide adenine dinucleotide phosphate (NADP<sup>+</sup>). Its products are D-xylono-1,5-lactone, reduced NADPH, and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is D-xylose:NADP<sup>+</sup> 1-oxidoreductase. Other names in common use include D-xylose (nicotinamide adenine dinucleotide phosphate), dehydrogenase, D-xylose-NADP<sup>+</sup> dehydrogenase, D-xylose:NADP<sup>+</sup> oxidoreductase, and D-xylose 1-dehydrogenase (NADP<sup>+</sup>).