The film "Tomorrow, When the War Began" was primarily filmed in various locations across New South Wales, Australia. Key filming sites included the Blue Mountains, Port Stephens, Raymond Terrace, Maitland, and the Hunter Region. Some scenes were also shot at Disney Studios in Moore Park, Sydney. Specific town settings such as Raymond Terrace were used to represent the fictional town of Wirrawee, with streets transformed to fit the film's narrative. Additionally, scaled-down explosions were filmed in Terrey Hills, northern Sydney.

There are also Victorian locations like Clunes, the Dandenongs, and Barwon Heads used in the related television series adaptation, but for the 2010 film, the New South Wales locations were the principal filming sites.