Australia’s historical aerial photography (HAP) collection constitutes one of the country’s longest-running environmental records, but it is dispersed across federal and state agencies with distinct catalogues and licence terms. This study presents the first synthesis of Australian HAP metadata. Records from four catalogues were combined to create a single database of almost 30,000 surveys spanning 1928 to 2019. Coverage is near-ubiquitous at coarse scales (95.4% of the continent) but drops to roughly 23% at the 1:25,000 threshold needed for detailed geomorphic and vegetation work, with the finest imagery concentrated in populated coastal regions. The synthesis demonstrates that cross-agency integration is tractable, though inconsistent quality reporting across catalogues constrains a full assessment of the imagery’s utility.