Do Australia passport holders need a visa to visit SD?

Yes, Australian ordinary passport holders need a visa to enter Sudan. There is no eVisa or visa-on-arrival for tourists; you must apply in advance through the Embassy of the Republic of Sudan in Canberra. Note: the Australian Government (Smartraveller) advises "Do not travel" to Sudan due to ongoing armed conflict. Australian citizens holding an ordinary passport require a visa to travel to Sudan for tourism or any short visit. Sudan does not offer an eVisa, electronic travel authorisation, or visa-on-arrival channel to Australians; the only route is a sticker/stamp visa obtained in advance from the Embassy of the Republic of Sudan in Canberra. The standard entry visa application requires a completed and signed form, two passport photographs, a passport valid for at least six months, and supporting documents including a letter of invitation from a Sudanese sponsor (with a copy of the sponsor's national ID) or, for tourists, a signed letter from a Sudan-based travel agent confirming accommodation. Many applicants also need an "Entry Document" issued by Sudan's General Directorate of Passports and Immigration via the sponsor. The embassy lists a non-refundable fee of AUD 200 and processing of up to 10 working days when the application is complete; incomplete applications are rejected outright. The visa is generally valid for two months from issue and permits a stay of up to two months from the date of entry. Critically, this route is largely theoretical for ordinary tourism right now: Smartraveller maintains its highest "Do not travel" advisory for all of Sudan because of the ongoing armed conflict between the Sudanese Armed Forces and the Rapid Support Forces, widespread civil unrest, terrorism, kidnapping risk, and the presence of landmines. Australia has no embassy in Sudan, with limited consular assistance provided remotely from the Australian Embassy in Cairo. Travellers should treat Sudan as effectively closed to leisure tourism and verify all details directly with the Sudanese embassy and Smartraveller before making any plans.