Sir Charles Edward Kingsford Smith, nicknamed Smithy, was an Australian aviation pioneer. He piloted the first transpacific flight and the first flight between Australia and New Zealand.

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.