Police were called to a home on Charles Street in Kirwan, Townsville about 7pm (AEDT) following a concern for welfare call from a relative outside the home.
Upon arrival, officers found the boy dead.
A 24-year-old woman known to the boy has been charged with murder and is due to appear before Townsville Magistrates Court today.
Detective Senior Sergeant David Miles said the boy had been staying at the residence and was being cared for by the charged woman.
Miles could not confirm if the woman, 24, was a blood relative of the child but said there was a “loose family connection”.
He said the child’s head injury appeared to be blunt force trauma, however an autopsy is yet to be completed.
“The child has suffered a significant head injury, which was obvious,” Miles said.
“At the moment, the injury is consistent with what I would say at this stage appears to be blunt force trauma.
“We will await the outcome of the autopsy before we make an absolute determination what weapon may have been used.”
Miles described the scene as “confronting” and “quite abhorrent”.
The boy’s time of death still remains unknown however police believe the injury was sustained within eight hours of officers being called.
The charged woman did not call triple zero or alert police to the dead child.
“[The call] came from a call from another relative with whom the 24-year-old had a conversation with, who alerted QAS and QPS to the scene,” Miles said.
Other children were also present at the home when police arrived, Miles said.
The 24-year-old woman is mother to those children and they have been removed from the home and are under care.
The home remains a crime scene as police continue to investigate the alleged murder.
The charged woman was taken into custody at the scene without incident, police said.