Since 1977, Canadian citizens have been allowed to hold dual nationality. If you were born (as the first generation born) in Australia after February 14, 1977, and your father can show he was a Canadian citizen BEFORE you were born, you should not have any problems getting a Canadian passport. You will need an original of your Dad’s Canadian Certificate of Citizenship and YOUR birth certificate from your home State in Australia. You will require a supporting letter from your mother, stating that she gave birth to you, where and when.
You will need to be registered with the Canadian embassy and you must apply for a Certificate of Canadian Citizenship for a child born outside Canada. This is required as your proof of citizenship when applying for your Canadian Passport.
Please contact the high commission of Canada in Canberra or Sydney for further information: