The 17-month-old boy fell over a balcony railing from a high-rise apartment on Thorncliffe Drive near Don Mills Road at about 9:30 p.m.
There are reports the boy had climbed onto a chair to peek over the railing.
The child was taken to Sick Kids hospital and was awake during the trip.
Police say the toddler will undergo a CT scan today. Police have ruled the fall as accidental.