Jamestown is in the South Australian Legislative Assembly electoral district of Stuart and the federal Division of Grey.

Sir John Cockburn was the town's first mayor, doctor, and later Premier of South Australia in 1889–1890.

[citation needed] Jamestown is the birthplace of Australian bush legend, Reginald Murray Williams (1908–2003), better known as R. M. Williams, the bush outfitter; Sir Raphael Cilento (1893–1985), tropical medicine pioneer, noted public servant and father of actress Diane Cilento; Paul Cronin (1938–2019), actor; and Edgar Mayne (1882-1961), test cricketer.

[citation needed] Jamestown has proud military history, with monuments featured within the township.

In 1918 the Cannon was ceded to the 9th Australian Light Horse Regiment in the initial distribution of captured weapons.