Western Australia Day is observed on June 04, 2018. The day was known as Foundation Day until 2012. At that time it was renamed, due to a series of law changes recognizing Aboriginal Australians as the original inhabitants of Western Australia. The day is a public holiday in Western Australia. It is celebrated annually on the first Monday in June. Due to this celebration, Western Australia does not celebrate the Queen's Birthday Holiday in June, but in September or October. Western Australia Day commemorates the founding of the Swan River Colony in 1829.