Glucose 6-phosphatase is an enzyme in the glycogenolysis pathway that removes the phosphate from glucose 6-phosphate. Also is the last step in gluconeogenesis where the goal is to increase free glucose in the blood due body being in catabolic state.

The main purpose of glucose 6-phosphatase is to dephosphorylate glucose 6-phosphate so that the free glucose can be exported from the cell via glucose tranporter membrane proteins.

Glucose 6-phosphatase is found in the liver and kidney and is involved in the organs' role in glucose homeostasis. Muscle and brain do not contain glucose 6-phosphatase; as a result any glucose 6-phosphate produced by glycogenolysis is used to generate ATP via glycolysis.

A deficiency in glucose 6-phosphatase can lead to von Gierke's disease.