IMSLP Forums

I want reassurance that Robert Leroy Johnston's "Sweet Home Chicago" and Hank William's "Your Cheatin' Heart" are in the Public Domain in Australia, both of these composers died before 1955.

They would be public domain - assuming that Hank Williams and Robert Johnson are the only names associated with whatever work you're considering. If there was another person associated with the work (arranger, author of text adaptation, etc.) who died after 1955, it might not be free after all.