The Legal Voting Age In Australia Is currently 18 years old and is comepletely compulsory. Making it optional for young voters makes sure that our young people are heard. Compulsory Voting is an extremely important law, but the reason governments may not have introduced younger voting because they think younger people aren't ready. Making it optional for young voters makes sure that who is ready to vote, can vote. And whoever is unsure, doesn’t have to.