STORY: Centre-left Labor held a decent lead going into the campaign after nine years in opposition, but recent polls showed Prime Minister Scott Morrison's Liberal-National government narrowing the gap in the final stretch of a tough, six-week campaign.
In-person voting at polling booths in suburban schools, beachside pavilions and outback halls opened at 8 a.m. (2200 GMT on Friday) and will close at 6 p.m. (0800 GMT).
One local resident at a polling station in Sydney who gave his name as Andrew said foreign policy was a concern for him:
"Look, I think fundamentally for me it's about actually engaging with a lot of the international sort of bodies that Australia has stepped away from."
While other voters said there needed to be more focus on tackling the climate crisis.
Voting is compulsory and initial results should be known by Saturday evening, although the Australian Electoral Commission has flagged that a clear winner may not immediately emerge if it is a close contest due to the time required to count about 3 million postal votes.