The blue-gray mouse is an Australian rodent species that is only known by a few specimens found in Eastern Australia, and since presumed to have become extinct.
A species of Pseudomys, these Australian rodents resembled the familiarhouse mouse. The body of P. glaucus was robust with fine and dense fur, white at the underside and a pale blue-grey colour over the upperparts of the fur. The measurement of each of the three known specimens was 95 millimetres for the head and body combined, with a white-hairedtail that was slightly longer The weight range was 25 to 30 grams.