The fourth season of Australian Idol began on 6 August 2006 and concluded on 26 November.

Australian Idol is an Australian singing competition, which began its first season in July 2003 and ended its initial run in November 2009. As part of the Idol franchise, Australian Idol originated from the reality program Pop Idol, which was created by British entertainment executive Simon Fuller. Australian Idol was televised on Network Ten for its first seven series and was broadcast on the Southern Cross Austereo Radio Network between 2005 and 2007. The series returned in 2023 after Seven Network announced they would be picking up the show.