In enzymology, an ADP-sugar diphosphatase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are ADP-sugar and H<sub>2</sub>O, whereas its two products are AMP and alpha-D-aldose 1-phosphate.
This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides. The systematic name of this enzyme class is ADP-sugar sugarphosphohydrolase. Other names in common use include ADP-sugar pyrophosphatase, and adenosine diphosphosugar pyrophosphatase. This enzyme participates in 3 metabolic pathways: fructose and mannose metabolism, purine metabolism, and starch and sucrose metabolism.