The Australian twenty-dollar note was issued when the currency was changed from the Australian pound to the Australian dollar on 14 February 1966. It replaced the £10 note which had similar orange colouration. There have been only three different issues of this denomination: a paper note which had a gradient of yellow and red, with a distinct orange background, and two designs of polymer note which can be recognised for their distinct red-orange colouration, and so it was nicknamed a "lobster". The first polymer note was issued on 31 October 1994 and the Next Generation polymer banknote was issued on 9 October 2019.

John Flynn was an Australian Presbyterian minister who founded the Australian Inland Mission (AIM) which later separated into Frontier Services and the Presbyterian Inland Mission, as well as founding what became the Royal Flying Doctor Service, the world's first air ambulance.