You need a visa for São Tomé and Príncipe if you have an Australian passport
Visa options for São Tomé and Príncipe
Electronic visitor visa
Travellers need a visa to visit Sao Tome and Principe for Business or Tourism. An eVisa is the fastest and easiest way of obtaining a visa for Sao Tome and Principe because travellers can submit their application and supporting documents online. Once the application is approved, travellers receive their eVisa confirmation electronically. A valid visa is required to board the flight. If the visa is expired or doesn’t match the traveller’s passport information, travellers will not be able to board their flight.