In enzymology, a hydroxypyruvate isomerase () is an enzyme that catalyzes the chemical reaction
Hence, this enzyme has one substrate, hydroxypyruvate, and one product, 2-hydroxy-3-oxopropanoate.
This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases interconverting aldoses and ketoses. The systematic name of this enzyme class is hydroxypyruvate aldose-ketose-isomerase. This enzyme participates in glyoxylate and dicarboxylate metabolism.