In April 1840, a mass killing of Aboriginal people occurred near what is now the Konongwootong reservoir, then known as Den Hills creek, close to present-day Coleraine in Victoria, Australia. The victims were members of the Konongwootong Gundidj clan of the Jardwadjali people, and reports of the death toll vary from "numerous" up to 40 or 60 people.
The massacre followed an earlier incident on 1 March 1840 known as the Fighting Hills massacre, in which the Whyte brothers—William, George, Pringle, and James Whyte, who operated the Konongwootong sheep run—and their servants were involved in killing Aboriginal people. Aboriginal Protector Charles Sievwright investigated that earlier incident but was unable to obtain evidence from independent witnesses, even though participants gave depositions admitting to the killing.
On 1 April 1840, after members of the Konongwootong Gundidj clan allegedly stole sheep, the Whyte brothers and station hands Henry Skilton and William Fox set out to find those responsible. Having failed to locate either the sheep or the Aboriginal people, the Whyte brothers rode to the nearest station while the remaining station hands continued toward the home station. Along the way, the station hands encountered a camp of "numerous old men, women and children" near waterholes. The station hands killed all members of the camp.
After news of the killings spread, the Whyte brothers dismissed the station hands involved. The surviving members of the Konongwootong Gundidj clan eventually relocated to Murndal station, where they joined the Wanedeet Gundidj clan. Later news accounts attributed the massacre to a retaliatory action organized by the Whyte brothers in response to the killing of a white shepherd in the Merino Downs area, though this attribution appeared in later reporting rather than at the time.
In 1946, a heavy flood uncovered skulls and bones at the site, which were discovered by T. J. Fitzgerald. The remains were later reburied.
In 2014, a commemorative site called the Konongwootong Quiet Place was established at the Konong Wootong reservoir to acknowledge the massacre. No individuals have been charged or convicted in connection with these killings, which occurred under British colonial administration of the Port Phillip District in 1840.