Blackboy Hill was named after the Australian native "black boy" plants, Xanthorrhoea preissii, which dominated the site which is now absorbed into Greenmount, Western Australia.
Originally a military camp, the facilities and adjacent structures were on the hill that is now used by St Anthony's Primary School and Church, and Greenmount Primary School. The remaining land (which has been left as a memorial to the troops who used the training camp) is known on official documents and maps as the Blackboy Hill Commemorative Site, but local signage tends to refer to the location simply as Blackboy Hill.
During the troop build up for the First World War, the site was a military training camp used to house large numbers of Australian Imperial Force (AIF) troops before they left for the various battlefront locations in Europe and the Middle East. Facilities were moved from other parts of the metropolitan area to improve facilities which were quite basic.
Troops were transported to the adjacent Helena Vale Railway station and marched across to the camp, so as to not interfere with the working of the Eastern Railway.
Blackboy Hill Post Office opened on 29 August 1914 and closed on 30 November 1918, defining the period of occupation of the site. An office of the same name was opened from 1929 until 1932, when it was renamed Greenmount Hill.
Around April 1919, following the end of hostilities, the Imperial forces camp was turned over to the Health department to act as a fever hospital, treating Spanish Flu.
In the 1930s unemployed relief workers utilised the camp area.
During the Second World War, the site was also used extensively by the 2nd AIF and other Australian military forces.
Blackboy Hill was a named railway stopping place between Bellevue and Swan View between the 1940s and 1960s, it was not related to the training camp or first world war troop movements.