While 50 children are still languishing on Nauru, the immigration department has released the last children in detention on the Australian mainland.
There are no longer any children in immigration detention in Australia but 50 are still languishing on Nauru.
Immigration Minister Peter Dutton has confirmed no children are being detained on the mainland for the first time in a decade.
"I'm very proud of the fact we've been able to stop the boats and get children out of detention," Mr Dutton told reporters in Brisbane.
"I feel a great sense of achievement in doing this."
The last group - which included a baby, a toddler and a 17-year-old - left Darwin's Wickham Point detention centre on Friday.
Under the previous Labor government the number of asylum-seeker children in detention in Australia peaked at close to 2000 in mid-2013 and a total of 8500 kids spent time behind razor wire.
Mr Dutton said the last few cases had been complicated because they involved one parent being subject to a negative security assessment from the national spy agency but the whole family had been in detention so they wouldn't be separated.
Mr Dutton said in those instances the father remained in detention because of ASIO security concerns but the mother and children were now in the community.
Asked about the plight of children on Nauru, Mr Dutton said the federal government was working to secure arrangements with third countries to take asylum seekers and refugees from the Pacific island because they wouldn't be coming to Australia.
He insisted the children were getting healthcare and education access on the island.
He denied reports his department had reclassified some sections of detention centres as community detention to make the no-kids-in-detention claim.
"The same definitions apply as they did before," Mr Dutton said.
Australian Greens senator Sarah Hanson-Young called on the minister to clarify whether children were still being held in the Villawood detention centre.
Labor deputy leader Tanya Plibersek said her party was delighted there were no children in detention in Australia.
"What shocks me is that processing times have blown up to 445 days under this government," she said.
Victorian Premier Daniel Andrews, who recently volunteered his state to house asylum-seeker families facing deportation to Nauru, said the release of children sent a good message to the world that Australia could be better.
"I would now say to Minister Dutton and Mr Turnbull why don't you go one step further and let them stay?" he told reporters in Melbourne.