Emergency crews were called to a residential apartment building in Scarborough on Friday evening for reports of a fire.
According to the Toronto Police Service (TPS), a woman in her 60s was transported to a hospital with serious, but non-life-threatening injuries.
Officers were called to the building near Lawrence Avenue East and Kingston Road just after 7:30 p.m.
TPS say the blaze potentially started on a balcony.
No other details were released.