磷酸甘油酸脱氢酶（英语：phosphoglycerate dehydrogenase，EC 1.1.1.95），是一种以NAD或NADP为受体、作用于供体CH-OH基团上的氧化还原酶。这种酶能催化以下两种酶促反应：

在大肠杆菌（Escherichia coli）中，磷酸甘油酸脱氢酶参与催化丝氨酸生物合成的磷酸丝氨酸途径中的第一步，上述可逆反应主要逆向进行。磷酸甘油酸脱氢酶可被丝氨酸或甘氨酸抑制。这种酶很不寻常，因为它还能像D-2-羟基戊二酸脱氢酶和L-2-羟基戊二酸脱氢酶一样还原α-酮戊二酸，其中，D型底物更适合磷酸甘油酸脱氢酶。

In enzymology, D-3-phosphoglycerate dehydrogenase (PHGDH) (EC1.1.1.95) is an enzyme that primarily catalyzes the chemical reactions

Thus, in the first case, the two substrates of this enzyme are 3-phospho-D-glycerate and NAD, whereas its 3 products are 3-phosphohydroxypyruvate, NADH, and H; in the second case, the two substrates of this enzyme are 2-hydroxyglutarate and NAD, whereas its 3 products are 2-oxoglutarate, NADH, and H.