The CAC Mustang is an Australian variant of the North American P-51 Mustang. It was built under license by Commonwealth Aircraft Corporation in the final stages of World War II, and though it was too late to see combat, it did participate in the Occupation of Japan after VJ-Day.

In late 1946, CAC received a contract to build 170 (later reduced to 120) Mustangs locally from scratch. These aircraft carried the new designation CA-18, with the first 40 being designated Mustang Mk 21 and powered by Packard V-1710-7 Merlins. 66 Mustang Mk 23s followed with British-built Rolls-Royce Merlin 66 or 70 engines. 14 Mustang Mk 22 reconnaissance aircraft were built with F24 cameras, and a further 14 were converted from Mk 21s