Mr Morrison's ruling coalition holds 76 seats in the House of Representatives - the minimum needed to retain power.
Polls suggest there will be a change of government, with the opposition Labor Party, led by Anthony Albanese, tipped to take office.
However, in the last election, the centre-right Mr Morrison won despite most polls predicting otherwise.
Mr Morrison announced the date after talks with the Governor General in the capital, Canberra.
"It's a choice between a strong future and an uncertain one. It's a choice between a government you know and a Labor opposition that you don't," the prime minister said on Sunday.
But Mr Albanese - pointing out Mr Morrison's own deputy prime minister called him "a hypocrite and a liar" - argued that "we can and must do better".
"The pandemic has given us the opportunity to imagine a better future and Labor has the policies and plans to shape that future," he said on Sunday.
Mr Morrison is the first leader to serve a full term in office since John Howard, who won four elections before losing to Labor's Kevin Rudd in 2007.
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