The boy, named locally as Charlie Joyce, died following the collision in the Dunclug area late on Thursday afternoon.
Another boy, aged 13, who was involved in the collision was last night understood to have been fighting for his life.
People who were in the area at the time rushed to try and help the two children before the arrival of emergency services.
The air ambulance was among three emergency crews that responded.
Both boys were taken from the scene to the Royal Victoria Hospital in Belfast — one in the helicopter and the other in a road ambulance.
Sadly, Charlie Joyce died as a result of his injuries.
The PSNI said that a full investigation had begun and asked that anyone who witnessed the crash, or had mobile phone footage, to come forward.
Fr Patrick Delargy, parish priest of All Saints’ Church in Ballymena, visited the Joyce family on Friday.
The cleric said the boys’ parents were in shock following the tragic death of their little boy.
“They were totally exhausted, they were coming back from hospital,” he told BBC NI.
“They find it very hard to process the whole matter.
“There are not the words, I find it very hard to find the right words to say in those situations.”
Fr Delargy said he prayed with the family and he believed it brought them some comfort.
The priest also expressed hopes the injured boy would recover.
Yesterday, other children in the Dunclug area had gathered around a makeshift memorial, where the words ‘RIP Charlie Joyce’ were written and bouquets of flowers were laid.
Fr Delargy expressed support for the idea of a permanent memorial on the spot where the crash happened.
Fr Delargy said: “It would be a good idea to have something there to remember the boy, and please God, the other little boy recovers. It would help people very much.”
In a statement, the Northern Ireland Ambulance Service said it responded to a 999 call at 4.47pm on Thursday.
“NIAS despatched three emergency crews and a doctor to the scene and also tasked the Charity Air Ambulance, with HEMS (Helicopter Emergency Medical Service) crew on board, to the incident,” said the statement.
“Following assessment and initial treatment, one child was flown by Air Ambulance to the Royal Group of Hospitals in Belfast while the other was taken to the same location by ambulance.”
Ian Paisley, DUP MP for North Antrim, said the families involved were in his prayers.
Sinn Fein MLA Philip McGuigan expressed his condolences.
“The local community has been shocked and saddened at this tragic death. It is particularly devastating given the age of the young boy,” Mr McGuigan said.
“My thoughts and sympathies are with his family, his young friends and his loved ones.”
Alliance MLA Patricia O’Lynn described the incident as a “tragedy”.
“The entire North Antrim Alliance team sends our thoughts and condolences to the family at this difficult time,” she said.
Tributes were pouring in on social media for the deceased little boy on Friday.
One family friend wrote: “Heaven gained a very special angel with a beautiful smile and beautiful nature.
“Charlie Joyce, in the arms of the angels now.”
She added: “God help all his family who are deeply heartbroken, rest in peace beautiful boy.”
Local boxing club, All Saints ABC, wrote: “This morning we woke to the tragic loss of one of our All Saints young guns. Our thoughts and prayers are with the Joyce family.”
The Doury Road Development Group, meanwhile, said it had moved to cancel a ‘Fairy GoodWood Children’s workshop’ scheduled for today as a “mark of respect for the family and friends of young Charlie Joyce.”