Australia

Australia map

Region: Australia and New Zealand

Requirements

Passport Validity
Must be valid at time of entry
Stay and Departure
Travel to Australia with an Electronic Travel Authority and a one-way airline ticket is permitted.
Transit
- The Transit visa (subclass 771) permits transit through Australia for no longer than 72 hours.
Dual Nationality
U.S. policy on dual nationality can be found here.

Additional Notes

  1. This information is only for one type of visa: the Electronic Travel Authority (subclass 601). This visa allows multiple entry for tourism or business, for up to a year, and stays up to three months for each visit. Work is not permitted on this visa. Penalties for deliberately breaching a visa condition include visa cancellation or being banned from returning to Australia for up to three years.
  2. Travelers with criminal convictions in any country, should apply for a Visitor visa (subclass 600), rather than an Electronic Travel Authority, to avoid being refused entry.
Sources:

Warning from Timaticweb

There is no physical evidence of an ETA in the passport. An ETA is verified electronically by ETA participating airlines prior to boarding and by immigration officials on arrival in Australia....

Warning: ensure the air carrier is ETA capable and can verify the ETA for boarding ("screen prints" of an ETA are not acceptable).