The group included two Rohingya families with five children.
Over 1500 people, including more than 120 children, remain in offshore detention on Manus Island and Nauru, more than half of them from Muslim majority countries banned from the US.
The refugee advocate Ian Rintoul said several Iranian and Somali refugees were refused US resettlement in the last two weeks.
Thousands of people marched in rallies across Australia on Saturday to expose the myth that their government had third country resettlement options for the refugees it had detained offshore for five years, he said.
"There is no US deal that is going to resettle the majority of refugees on Manus and Nauru," said Mr Rintoul spokesperson for the Refugee Action Coalition.
"The government has created a humanitarian crisis in its offshore prisons. We need urgent action to bring all the refugees and asylum seekers from Nauru and Manus Island to Australia."
The Kurdish journalist and Manus Island refugee Behrouz Boochani sent a message to the protesters commending them for opposing their government's lack of humanity and compassion.
"They want to replace human values with violence, immorality and humiliation. They are exploiting innocent people and damaging Australia's national character for their own political aims," Mr Boochani said.
"But we know that people like you won't let them. Today you are saying that this unlawfulness is enough, this violence is enough, this loss of life, of hope, of kindness and compassion is enough," he said.
"Each of you is a hero in this dark historical period. Your children and grandchildren should be proud of you, either now or in the future, for standing up for what's right, both for us here in Manus and Nauru and for a better, kinder, more compassionate Australia."