The fourth series of the Australian cooking game show MasterChef Australia premiered on Sunday, 6 May 2012 at 7.30pm on Network Ten. Judges George Calombaris, Gary Mehigan and Matt Preston returned from the previous series. After the first week in Melbourne, the competition took the contestants to places nationally, such as Kangaroo Island and Tasmania, as well as the international destination, Italy. It also featured a number of guest chefs, including Jamie Oliver, Rick Stein and Buddy Valastro.