The American pro-Trump influencer was fatally shot on Wednesday US time while speaking at a university event in Utah, prompting an outpouring of grief from some political leaders and broad condemnation of the violence.
"This is horrific," Prime Minister Anthony Albanese told reporters in Cairns on Friday.
"I think the world is shocked by such an event, and my heart goes out to Mr Kirk's family."
Mr Kirk co-founded Turning Point USA, a conservative advocacy group which was active on university campuses and often found viral fame on social media.
The organisation's Australian branch will hold a vigil in Sydney's Hyde Park on Friday to honour his "memory and legacy."
"Charlie Kirk was brave and committed to fighting battles through discourse rather than violence," Turning Point Australia's national director Joel Jammal said  in a statement.
"Violence is never the answer to political disagreement and diminishes the very principles that democracy is built on."
Mr Albanese said people with a grievance should have their say "through the ballot box," and criticised Australia's political "fringes."
"We need to continue to get rid of the fringes, whether they be of the extreme left or the extreme right, but there is no place for political violence," he said.
Independent MP Allegra Spender said Australians need to invest in "listening to each other and disagreeing in a constructive way," to avoid making political violence more common.
"You can't end up in this sort of division and the sort of violence that we have seen in the US... it's frightening," she told Nine's Today Show.
Notable Australians including NRL player Jarome Luai and former prime inister Tony Abbott are among those paying tribute to Mr Kirk.
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