While the economy is a key issue, several so-called “teal independents” are challenging key Liberals seats and campaigning for action on climate change after some of the worst floods and fires to hit Australia.
In the outgoing parliament, the Liberal-national coalition had 76 of the 151 seats in the lower house, while Labor had 68, with seven minor party and independent members.
Voting is mandatory and first results should be out by Saturday night, although the Australian Election Commission has marked a clear winner may not come out immediately if it is a close contest due to the time it takes to get around 3 million votes by post to count.
More than half of the votes had already been cast Friday night, with a record 8 million early personal and postal votes, the Australian Election Commission said.
A two-hour time difference between the east and west coasts means polls in Western Australia will still be open, as the first counts come from the densely populated states on the east coast, which hold 124 of the 151 lower house seats.