The enzyme 6-phospho-ò-galactosidase () catalyzes the following reaction:
This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name is 6-phospho-ò-<small>D</small>-galactoside 6-phosphogalactohydrolase. Other names in common use include phospho-ò-galactosidase, ò-<small>D</small>-phosphogalactoside galactohydrolase, phospho-ò-<small>D</small>-galactosidase, and 6-phospho-ò-<small>D</small>-galactosidase. This enzyme participates in galactose metabolism.
, four structures have been solved for this class of enzymes, with PDB accession codes 1PBG, 2PBG, 3PBG, and 4PBG.