Firefighters were called to 244 Gladstone Ave. just before 8 a.m. The three-storey building, located on Gladstone just north of Dundas Street West, appears to be a rooming house.
Firefighters found two people inside: a woman who was taken to hospital without vital signs and a man with serious burns to his body. Both are believed to be in their 40s.
A number of other people were rescued from the building.
The fire was extinguished just after 8 a.m.