The Bee Gees.
OK, they were made in pommy land, but were refined in Australia and then exported to the world. Barry once said the genre called disco was created from their music. It's not really true, because disco existed prior to the Bee Gees taking up the genre. But their music certainly promoted the genre.
We also created the antithesis of the Bee Gees... Dave and the Derros "Death to Disco", a great composition for discerning tastes in fine music. The Australian contribution to the death of disco.