How Long Can a U.S. Citizen Stay in Australia?
For a typical short visit using an eligible ETA, the answer is:
Up to three months at a time.
However, Americans who want to spend more time in Australia may need a different visa.
Australia’s Visitor visa (subclass 600) can be granted for stays of three, six, or up to 12 months, depending on the visitor’s circumstances and the decision made on the application.
For visitors that is applying from outside Australia, the government notes that a three-month stay is generally granted, although stays of up to 12 months may be granted in certain circumstances.
In simple terms:
Type of Australian travel permission==>
Possible length of stay
Electronic Travel Authority (ETA)==>Up to 3 months per visit
Visitor visa==>3,6,or up to 12 months, depending on the grant
Work or long-term visa==>Depending on the specific visa
So, Your exact permitted stay is determined by the visa or travel authority you are granted.
See here👇
Australia Visitor Visa (Subclass 600)�