List of Western Australian Legislative Assembly elections

This article provides a summary of results for elections to the Western Australian Legislative Assembly, the lower house in Western Australia's bicameral state legislative body, the Parliament of Western Australia, which came into being in 1890 when Western Australia achieved responsible self-government. The number of seats has increased over time, from 30 at its first election, to the current total of 59 seats. Western Australian politics were initially non-partisan, with individual Members of Parliament choosing to align either with the Government or the Opposition. This began to change in the 1901 election with the election of six Labor members, and then with Labor attaining outright victory in the 1904 election. By 1911, a rival party to Labor had emerged in the centre-right Liberal Party of Western Australia, which many of the former independents had joined. This entity evolved into the Nationalist Party and eventually into the Liberal Party in 1944.

The chart below shows the information graphically, with the most recent results on the right. It shows the popularity in terms of seats won, of the Labor Party (red) and the Nationalist Party and its predecessors (mid-blue) in the first half of the 20th century, as well as the emergence of the Country Party (green) in 1914, with whom the Nationalists and later the Liberals formed a coalition in order to form government. Two distinct periods were characterised by one party or coalition's dominance—the Labor Party won six of the seven elections between 1924 and 1947, and the Liberal Party (dark blue) in coalition with the Country Party won seven of the eight elections between 1959 and 1983. Occasional internal splits within the Country Party, now known as the Nationals, are also shown on the chart in differing shades of green.

Summary of results
The table below shows the total number of seats won by the major political parties at each election. The totals of the winning party or coalition are shown in bold, while other parties in government are shown in bold italic. Full details on any election are linked via the year of the election at the start of the row.

Elections prior to political parties
Until the 1904 election, most candidates did not belong to political parties. However, some candidates declared their support for the administration of the time, while others declared their opposition to it. Full details on any election are linked via the year of the election at the start of the row.

Interpretation issues
Two features of the Western Australian electoral system are worthy of note in interpreting election results. The first is that until the 1974 election, many seats in both houses were uncontested—usually more than one-quarter of all seats on offer. Since 1974, only three seats have been uncontested—that being the seats of Collie and East Melville in the 1980 election, when the rival party's candidates missed the nomination deadline and hence could not stand, and the seat of Narrogin in the 1983 election.

The second feature is malapportionment, which until 2008 was a significant feature of the Western Australian political landscape. Seats in metropolitan and rural areas did not contain the same number of electors—as at 30 September 2007, a Member of the Legislative Assembly represented either 28,519 metropolitan voters within the Metropolitan Region Scheme area, or 14,551 country voters. This was believed to disproportionately favour the Nationals in terms of parliamentary representation. Reforms enacted in 2005 which took effect at the 2008 election produced an average district enrolment of 21,350, which applied to all but five of the 59 districts created in the 2007 redistribution. An allowance remained for particularly large districts—those of 100000 km2 or more, located in the north and east of the State—in the form of a Large District Allowance.