A young boy has been killed after the ATV he was riding rolled on a private property in the state's South West.

Details are scarce but police say the 7-year-old boy was fatally injured after an ATV rolled on a private property in Dingup, which is near Manjimup.

Its understood police and St John Ambulance crews rushed the boy to the local hospital but he died a short time later.

Police were called to the property just before 2pm on Saturday.

Police are preparing a report for the coroner and the boy's family have been informed.