The townsite of South Boulder is located in the eastern goldfields region, 595 kilometres east northeast of Perth. It is within the Kalgoorlie-Boulder urban area. Gold was discovered in this area in 1893, and the townsite of Boulder gazetted in 1896. As the area grew demand for land increased, and in 1898 the Ivanhoe Suburban Area was gazetted south of Boulder. In 1906 the Postmaster General's Department decided to establish a post office at Ivanhoe, but first requested the name be changed because of two established towns of this name in the eastern states. Local authorities suggested South Boulder as an alternative, and the South Boulder townsite was gazetted in August 1906. South Boulder derives its name from its location south of Boulder. Boulder in turn derives its name from a mine named "The Boulder" at Dashwoods Gully in South Australia.