The now 13-year-old, who can't be named for legal reasons, has been in juvenile detention since February 2016.
He was sentenced to four years' jail but is eligible for supervised release halfway through his sentence in February 2018.
The boy was one of eight people who in the early hours of January 27, 2016 chased and attacked 26-year-old Patrick Slater, who was fatally stabbed with a screwdriver.
Several fights had broken out between the 11-year-old's group and Mr Slater's group following Australia Day celebrations in Perth.
That culminated in the boy and some older boys and men setting upon Mr Slater near Perth's Esplanade train station and killing him, with parts of the battle caught on security cameras.
The 11-year-old was the youngest known person in Australia's recorded history to have been charged with murder, prompting calls from Amnesty International to raise the age of criminal responsibility, in line with brain development research.
At the time, Nyoongar elder Ben Taylor told NITV News children were turning to alcohol and drugs in response to losing their culture.
"There are scars, they're scars of the White Australia policy, of being torn from your mother’s arms," the 76-year-old said.