Electoral districts of South Australia

Since 1970, the South Australian House of Assembly (the "lower house") has consisted of 47 single-member electoral districts consisting of approximately the same number of enrolled voters. The district boundaries are regulated by the State Electoral Office, according to the requirements of the South Australian Constitution and are subject to mandatory redistributions by the South Australian Electoral Districts Boundaries Commission in order to respond to changing demographics.

Boundary adjustments

Electoral boundaries are adjusted after each election. The number of electors in each district must be within 10% of the average at the time of the redistribution order. Other issues that may be considered include economic, social and regional communities of interest.[1] From 1990 to 2018, it was also a requirement that each redistribution attempt to ensure that the party that obtains 50% or more of the overall vote at a general election would be able to form a government; this requiremnet has since been repealed.

Election	1970	1973	1975	1977	1979	1982	1985	1989	1993	1997	2002	2006	2010	2014	2018
Govt	Labor	Labor	Labor	Labor	Liberal	Labor	Labor	Labor	Liberal	Liberal	Labor	Labor	Labor	Labor	Liberal
# of seats	27	26	23	27	24	24	27	22	37	23	23	28	26	23	25
% of seats	57.4	55.3	48.9	57.4	51.1	51.1	57.4	46.8	78.7	48.9	48.9	59.6	55.3	48.9	53.2
% of vote	53.3	54.5	49.2	53.4	55.0	50.9	53.2	48.1	61.0	51.5	49.1	56.8	48.4	47.0	51.9

While South Australia's total population exceeds 1.7 million, Adelaide's population exceeds 1.3 million − uniquely highly centralised, over 75% of the state's population resides in the metropolitan area and has 72% of seats (34 of 47) alongside a lack of comparatively sized rural population centres, therefore the metropolitan area is crucial in deciding election outcomes. At the 2014 election for example, although the statewide two-party vote (2PP) was 47.0% Labor vs. 53.0% Liberal, the metropolitan area recorded a 2PP of 51.5% Labor v 48.5% Liberal.^a

List of the current 47 electoral districts

Maps

Map of outer rural electoral districts showing results from the 2018 election.
Map of metropolitan and inner rural electoral districts showing results from the 2018 election.
Map of metropolitan electoral districts showing results from the 2018 election.

Numbers of electorates and members

Since 1938, the South Australian House of Assembly has had single-member electoral districts. From 1938 to 1968 there were 39 districts. Since 1970 there have been 47 electoral districts. From 1857 to 1933, the number of districts varied between 12 (1912–1915) and 27 (1890–1901). Each district returned from 1-6 members.

Parliaments	Years elected	Districts	Members
1, 2	1857, 1860	17	36
3, 4, 5, 6, 7	1862, 1865, 1868, 1870, 1871	18	36
8, 9, 10	1875, 1878, 1881	22	46
11, 12	1884, 1887	26	52
13, 14, 15, 16	1890, 1893, 1896, 1899	27	54
17, 18, 19, 20	1902, 1905, 1906, 1910	13	42
21	1912	12	40
22, 23, 24, 25, 26, 27, 28	1915, 1918, 1921, 1924, 1927, 1930, 1933	19	46
29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39	1938, 1941, 1944, 1947, 1950, 1953, 1956, 1959, 1962, 1965, 1968	39	39
40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53	1970, 1973, 1975, 1977, 1979, 1982, 1985, 1989, 1993, 1997, 2002, 2006, 2010, 2014, 2018	47	47