The four were handed minimum terms ranging from 13 years to 10 years at Antrim Crown Court for killing 15-year-old Michael McIlveen in Ballymena in May 2006.
Michael, known to friends and family as Micky Bo, was punched, kicked and beaten with a baseball bat in an alleyway after a row involving a group of Protestant teenagers.
He died hours later in hospital.
Earlier this year Aaron Wallace, 21, of Moat Road, Ballymena, Christopher Kerr, 22, of Carnduff Drive, and Jeffrey Lewis, 20, of Rossdale, also in the town, were found guilty of his murder.
At the start of the trial Mervyn Moon, 20, of Douglas Terrace, Ballymena, pleaded guilty to the murder.
On Friday, Judge Mr Justice Treacy sentenced all to life imprisonment.
The highest minimum tariff - the time to be served before being considered for release - was handed to Kerr, whom the judge said had shown no remorse for his actions and had lied consistently through the trial.
He said the fact that he had also gone to his grandmother's house to obtain the baseball bat showed his part in the murder was premeditated.
Wallace and Lewis were given 11-year tariffs - lesser terms because they had no part in procuring the bat or using it, the judge said.
Lewis was also given an additional one month in prison for a charge of criminal damage.
Mr Treacy gave Moon credit for his timely plea of guilty and that he had shown clear and genuine remorse for his actions. He was given a 10-year minimum tariff.
'Disappointed'
Outside the court, Michael's tearful sister Jodie said the family was deeply unhappy and disappointed with the length of the sentences that had been handed down.
"The McIlveen family are unhappy with the sentences imposed today, which we feel were too lenient. We all believe that life should mean life", she said.
"Michael lived for 15 years and not one of the defendants will serve this length of time for his death.
"Whilst every defendant in the case now knows when their life will start again, as a family our lives will never be the same again without Michael."
'Lethal cocktail of drugs'
Mr Treacy said Moon had taken five cannabis joints, a half bottle of vodka and three alco-pops on the day the victim was beaten to death.
He added this lethal cocktail of drugs, drink, youth and sectarianism provided the context in which the murder took place.
Christopher McLeister, 18, of Knockeen Crescent, Ballymena, was given a three-year sentence suspended for two years for the manslaughter of Michael.
Paul Hanson, 18, of Condiere Avenue, who was found guilty of affray and criminal damage, was sentenced to a total of 10 months while Peter McMullen, 18, of Meadowvale, Ballymena, who the jury had cleared of murder by direction of the court, was given a conditional discharge for causing criminal damage.
In a packed court, Mr Treacy described the death of Michael as "a brutal and sectarian murder".
The judge acknowledged the pain the killing had inflicted on the McIlveen family.
"As I have said, Michael was only 15 at the time of his murder and its devastating impact on his entire family has been set out in a moving victim impact statement signed by his mother," he said.
In her statement to the court, Michael's mother, Gina, said: "For anyone to have their son taken from them so suddenly is a horrendous experience, but for it to occur in such a violent manner and the public attention that followed, only magnifies it.
"I personally have found Michael's death extremely difficult to deal with. My health suffered and there are times when I have not been able to cope."
She said she sympathised with the families of those convicted in connection with her son's murder.
She added: "Michael was a brilliant wee fella and we were very close. He was happy-go-lucky and always had a big smile.
"He is in our thoughts first thing in a morning and last thing at night."
The family statement was included in Mr Treacy's judgment.