The La Grange expedition was a search expedition carried out in the vicinity of Lagrange Bay in the Kimberley region of Western Australia in 1865. Led by Maitland Brown, the expedition searched for three settlers who had failed to return from an earlier exploring expedition. The three men were eventually found dead, having been speared and clubbed to death in their sleep by Indigenous Australians. A number of Indigenous people were subsequently killed by members of the expedition in a controversial incident that is often now referred to as the "La Grange Massacre", although the fairness of this term remains a matter of some debate.
In 1864, an expedition was organised to investigate the story of a convict named Henry Wildman, who claimed to have found gold near Camden Harbour. The expedition found no gold, but good pastoral land was found, and as a result a small pastoral venture was later established at Roebuck Bay. In November 1864, three settlers, Frederick Panter, James Harding and William Goldwyer, set out from the settlement to explore the land around La Grange Bay. The expedition party had provisions to last only two to three weeks, so when they had not returned three weeks later, another settler, Lockier Burges, set out to find them. He tracked them as far as the mangrove swamp around La Grange, but there lost all trace of them.
When news of the missing men reached the Government of Western Australia in Perth, a search party was immediately organised, with Maitland Brown appointed leader. There was some speculation that the three men had been killed by natives, and there were calls for their deaths to be avenged. George Walpole Leake, for example, wrote: