The Hume and Hovell expedition was one of the most important journeys of explorations undertaken in eastern Australia. In 1824 the Governor of New South Wales, Sir Thomas Brisbane, commissioned Hamilton Hume (a native-born Australian) and former Royal Navy Captain William Hovell to lead an expedition to find new grazing land in the south of the colony, and also to find an answer to the mystery of where New South Wales's western-flowing rivers went to.

The party set out from Appin near Sydney in October 1824, and travelled south to the Murrumbidgee River near the site of Tumut (contrary to many accounts they were not the first Europeans to see the Murrumbidgee). In November they discovered what they called "a noble stream" which they named the Hume (now the Murray River) near the site of Albury, and then advanced into what is now Victoria.

In December Hume and Hovell crossed the Victorian ranges, and were able to see the sea from the hilltops. Soon they arrived at Corio Bay near the present site of Geelong. They mistakenly believed they had reached Western Port, the large bay further east which had been discovered by Matthew Flinders and George Bass in 1798.

Relations between the "currency lad" (native-born) Hume and the aloof Englishman Hovell had deteriorated, and they raced each other back to Sydney to claim credit for their discoveries. They arrived in January, and were both rewarded with large land grants by Governor Brisbane. They later published conflicting accounts of the journey, each claiming leadership, but today Hume is much the better remembered of the two.

The Hume and Hovell expedition disproved the widely held view that the interior of Australia was an unihabitable wilderness. They found abundant well-watered grazing land between the Murrumbidgee and the Murray, and also in Victoria. Soon streams of settlers were following their route, which is now the Hume Highway from Sydney to Melbourne via Albury. But their expedition only deepened the mystery of the western rivers.