It is believed a man attended the centre to pick up his child but, after being told the child was not there he returned to his car and found the boy in the back seat.
Staff from the day care centre immediately commenced CPR, but attempts to revive the child were unsuccessful.
Police and ambulance officers were called to the centre, on Torquata Boulevard, about 4pm.
The death is not being treated as suspicious but Major Crime Squad detectives are continuing investigations.
Centre general manager Kim Beange said staff were professional and vigilant.
‘Our staff’s professionalism came to the fore and they remained vigilant throughout this time, and at no point were other children in attendance aware of the circumstances occurring,’ she said.
‘All staff have been offered professional counselling and support services, along with further assistance as needed.
‘Our thoughts and condolences are with the parents of the child and their family through this tragic time.’
A report is being prepared for the Coroner.