The 2009 Western Australian daylight saving referendum was held on 16 May 2009 in the Australian state of Western Australia to decide if daylight saving time should be adopted. It was the fourth such proposal which had been put to Western Australian voters and followed a three-year trial period. The referendum resulted in the proposal being rejected, with 54.56% voting against the proposal.
Various states and territories in Australia adopted daylight saving time between 1968 and 1971, but Queensland, the Northern Territory and Western Australia did not do so. In Western Australia, three referendums were held in 1975, 1984 and 1992 on the issue, with daylight saving being rejected each time.
On 25 October 2006, two members of the Western Australian Legislative Assembly, former Labor minister turned independent member John D’Orazio and Liberal leader Matt Birney, introduced a private members’ bill for a three-year trial of daylight saving to begin in December 2006. The Labor government of Western Australia backed the trial and both main parties agreed to hold a free vote on the issue. Farming groups quickly came out against the move, along with the mining lobby, but the move was backed by business groups. The bill was approved by the lower house 37-14 and then by the upper house 21–10, enabling the trial to start from 3 December.
During 2007 there was growing opposition to daylight saving time with some in the National Party calling for people to ignore the trial. In October 2007 the Liberal Party proposed a bill to bring the referendum forward to early 2008 because of the backlash against daylight saving, and a petition was signed by 66,000 people supporting holding the referendum in 2008. However this was not successful and the referendum was called for 16 May 2009.