Grey's Wallaby was named after the explorer and South Australian Governor, Sir George Grey but it became known as the Toolache Wallaby. Its scientific name was originally Halmaturus greyi but is now Macropus greyi.

It was once abundant in south-east South Australia but competition with grazing livestock and hunting for sport and for its attractive skin, led to its extinction. According to Christopher Dickman in A fragile balance : the extraordinary story of Australian marsupials p. 228 the last wild individual was recorded in 1927, taken into captivity, and died in 1939.