In enzymology, a maltose phosphorylase (EC 2.4.1.8) is an enzyme that catalyzes the chemical reaction Thus, the two substrates of this enzyme are maltose and phosphate, whereas its two products are D-glucose and beta-D-glucose 1-phosphate.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases.

The systematic name of this enzyme class is maltose:phosphate 1-beta-D-glucosyltransferase.

This enzyme participates in starch and sucrose metabolism.

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 1H54.