I am an Australian with a Singapore permanent resident status, do I need a visa for Vietnam?
Yes you need a visa for Vietnam. Only Singapore passport holder can come to Vietnam for a 30 day visit without a visa (see full list of countries with visa exemption agreement with Vietnam).
Australians can get a visa to Vietnam in 2 ways: applying for one at the embassy in Canberra or consulate in Sydney. An alternative option is get one on arrival (read full instructions about how Australians can get a visa for Vietnam).
Hope this helps.