Robert Arthur Johnstone (1843 – 16 January 1905) was an officer in the Native Police paramilitary force which operated in the British imperial colony of Queensland. He was stationed at various locations in central and northern Queensland between 1867 and 1880 conducting regular punitive expeditions against clans of Indigenous Australians who resisted British invasion. He also participated in several surveying expeditions in Far North Queensland, including those under the leadership of George Elphinstone Dalrymple, providing well-armed protection for the British explorers. As a result of being at the frontier of British colonial expansion in this region of Australia, a number of geographical and zoological entities are named after him, such as the Johnstone River and the freshwater crocodil