Earlier this month, Barry Lyttle, from Ballycastle, County Antrim, pleaded guilty to recklessly causing grievous bodily harm.
He was filmed on CCTV punching his younger brother, Patrick, outside a nightclub in Sydney in January.
Patrick Lyttle spent a week in a coma but made a good recovery.
He had asked the court to show leniency to his attacker.
Outside court, Barry Lyttle said the family was now looking forward to going home to Northern Ireland.
He was not charged under new one-punch laws, which have mandatory sentences for alcohol fuelled assaults.
Tests had shown he had only a small amount of alcohol in his system.
Lyttle was given a 13-month suspended sentence and a good behaviour bond.
The magistrate said Lyttle had shown sincere remorse and was unlikely to reoffend.
He said: "This would appear not to be an act of alcohol-fuelled violence."
But he added that the community should not be subjected to violence and needed a clear message that it was not acceptable.
The brothers sat together in court with their father and hugged and cried when the verdict was handed down.
After the sentencing, Barry Lyttle said the "saga has been put behind us".
"It's been four months of absolute hell for the whole family and myself.
"I'd like to thank everybody for the support we've received here and back in Ireland.
"I'm also so proud of this man here [Patrick] as he's done incredibly well.
"We can go home and kick-start our lives again."
Patrick Lyttle said he was grateful his brother had been given a suspended sentence so the family could get their lives back to normal.
"[Barry] has been through an awful lot, not just myself," he said.
"We're close and we all love each other and that's never changed."
A Northern Ireland man who critically injured his brother in Australia has been given a 13-month suspended sentence.