A recent discovery at the 19th-century Hyde Park Barracks Destitute Asylum in Sydney provides the earliest securely recorded zooarchaeological evidence for the house mouse (Mus musculus) in Australia. While M. musculus probably arrived with the first European settlers in the late 18th century, securely dated examples from the colonial period are rare. Our find consisted of a wooden matchbox containing the well preserved skeletal remains of three mice, in a context dating to the period 1848–1886. The material is noteworthy for the excellent preservation of the bones, which include skulls, articulated vertebrae, ribs, innominates (pelvis) and distal hindlimb. This paper briefly describes the evidence for the arrival of M. musculus in Australia; the archaeological and historical context of the find; the nature and condition of the mouse skeletons; and possible interpretations. Copyright © 2011 John Wiley & Sons, Ltd.