It's believed he is now receiving treatment at the Royal Brisbane and Women's Hospital after being flown by Air Ambulance to Australia yesterday.
The Department of Home Affairs has confirmed the incident with SBS News and says the man is receiving all necessary treatment.
"The Department is aware of a self-harm incident that occurred (on Friday morning) on Nauru," a Department spokesperson said.
The man was treated at the Republic of Nauru Hospital before the decision was reportedly made to transfer him to Australia.
"The Australian and Nauru Governments will continue to provide support," the Department of Home Affairs said.
Refugee Action Coalition spokesperson Ian Rintoul says the drastic action paints a bleak picture of life in offshore detention.
"We are extremely concerned for Jamal's welfare," he said,
"Jamal's suicide attempt is yet another wake-up call for the Australian government. Jamal is another casualty of Australia offshore detention policy. After six years on Nauru, refugees have no secure future. They have lost hope."
Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14, Suicide Call Back Service on 1300 659 467 and Kids Helpline on 1800 55 1800 (up to age 25). More information about mental health is available at Beyond Blue.