Firefighters were called to Brussel Street, near Park Lawn Road and The Queensway, at around 2 a.m. for a ‘very smoky fire’ at a three-level home.
A Toronto Fire spokesperson said crews found and rescued one occupant.
After performing life-saving measures the patient was transferred to paramedics, the spokesperson said.
Toronto paramedics told Global News they transported a woman with life-threatening injuries to hospital.
Fire officials said the fire was extinguished and crews are continuing to clear the smoke.
The Ontario Fire Marshal’s office has been called in to investigate.