London fire crews responded to a balcony fire around 6 p.m. on Sunday in the downtown core.
Firefighters were able to quickly put out the flames and ventilate the apartment on Richmond Street north of Dufferin Avenue.
According to the London Fire Department, no one was home at the time of the fire and no injuries were reported.
A damage estimate has not yet been made available.
Fire officials believe careless disposal of smoking materials started the fire.