Foreign Minister Penny Wong has expressed concern at the sentencing of the activists, including Australian-Hong Kong dual citizen Gordon Ng.
The verdict has drawn international concern about the erosion of the rule of law.
"We are deeply concerned by the verdicts handed down today," Senator Wong said in a statement on Thursday.
"The Australian government raises consular and human rights concerns directly with the Hong Kong and Chinese governments regularly and at the highest levels.
"We will continue to do so, including in the case of Mr Ng."
The Australian government continued to request consular access to Mr Ng from Hong Kong authorities, Senator Wong said, as she noted he had appeal options and therefore, she could not comment further on the case.
The guilty verdicts were branded "appalling" by the opposition.
Opposition foreign affairs spokesman Simon Birmingham called the verdict appalling. (Mick Tsikas/AAP PHOTOS)
"The decimation of freedoms and rights in Hong Kong in recent years is a tragedy that cannot and should not be put in the rear view mirror," opposition foreign affairs spokesman Simon Birmingham said in a statement.
"The Chinese government's actions warrant constant and consistent pressure from Australia and nations which also valued the freedoms and rights that Beijing promised to uphold in Hong Kong but has instead destroyed."
Two Australian residents from Hong Kong who have bounties on their heads from authorities who sought their return needed to have their persecution dropped, Senator Birmingham said.
"The blatant destruction of individual human rights in Hong Kong cannot and should not be forgotten or accepted by Australia," he said.
"The coalition offers its strong bipartisan support for all actions that send a clear message opposing the diminution of rights and freedoms for the people of Hong Kong."
Australia had also expressed "strong objections" to the broad application of the national security law that has been used to arrest and pressure pro-democracy activists, Senator Wong said.
"We know that the application of these laws also has implications for individuals outside of Hong Kong, including in Australia," she said.
"The systemic erosion of Hong Kong's rights, freedoms, autonomy and democratic processes has been consistently raised with China and Hong Kong.
"We have called on Hong Kong authorities to uphold those elements which have been so crucial to Hong Kong's success."
Australia recommended to China it "cease suppression of freedoms of expression, assembly, media and civil society" during Beijing's universal periodic review in January.
This included a repeal of the national security law in Hong Kong.
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