The case was launched by a Bangladeshi detainee on Nauru who was brought to Australia for treatment and later gave birth to her daughter in Brisbane.
Lawyers for the woman argued that it was illegal for the Australian Government to fund and operate detention centres in a third country.
Mr Turnbull told Parliament the Government would consider the judgement, but noted that it upheld the existing framework as “legally and constitutionally valid”.
He said that the framework had kept Australia’s border secure and prevented drownings at sea.
“The people smugglers will not prevail over our sovereignty,” he said.
“Our borders are secure. The line has to be drawn somewhere and it is drawn at our border.”
During the High Court case the Government changed the law to close a loophole in the funding arrangements, which it feared could be undermined by the challenge.
Today a majority of the court’s bench found the current government arrangements were valid under the constitution.
Justice Michelle Gordon, the most recent appointment to the bench, issued the lone dissenting judgement that the laws rushed through in June were invalid.
Before the decision, Immigration Minister Peter Dutton flagged his intention to send a group of 160 adults, 37 babies and 54 children currently in Australia back to Nauru, should the Government win.