In no Particular order here are my choices out of the Bulletin’s top 100 Aussies (See below) for the top 10.
When John Flynn arrived as a young Presbyterian minister at the remote South Australian mission town of Beltana in 1911, he saw that people in the outback had no access to medical help, and no way of calling for it when it was needed. A year earlier he’d published with fellow minister Andrew Barber The Bushman’s Companion, an all-purpose almanac covering everything from what to say at funerals to basic medical treatment. It was a hit, and emphasised to him the isolation of the rural communities that he served. Beginning in 1917, he helped establish nursing stations across the outback and then began raising funds for an aerial service. A Sydney surgeon, Kenyon St Vincent Welch, became the first Flying Doctor in 1928, and in 1934 the Presbyterians transferred their medical work to the National Aerial Medical Service. The service couldn’t have functioned without the parallel development of the pedal radio by Alfred Traeger, which Flynn helped fund. The radio not only helped people call for assistance but allowed those who had previously relied on the post to stay in contact with neighbours and nearby townships. Flynn died in 1951, four years before the service was granted the royal imprimatur and renamed itself the Royal Flying Doctor Service.