Was one of your parents an Australian citizen on the day you were born?
Australia — Citizenship by Descent
Australian citizenship passes down one generation only, and it is your parent's status on the day of your birth that counts — not what happened later, and not a grandparent's citizenship.
Yes → No, but a parent became an Australian citizen later → No — the Australian in my family is a grandparent or further back → No, and there is no Australian anywhere in my family → I'm not sure →
Question 2 · start again