The fire at 2575 Danforth Ave., near Main Street, was reported at 4:30 a.m. on Wednesday.
It was brought under control by firefighters and contained to the apartment unit where it started — the same unit where the alleged grow-op was located.
Toronto police allege the fire started as a result of the ongoing marijuana production.
Police say that the tenants tried to put the fire out, but were unable to do so.
Drug equipment and marijuana plants were seized in the aftermath of the fire.
Two 22-year-old Toronto men face charges that include mischief endangering life and arson having disregard for human life. Both of the accused appeared in court on Thursday.
None of the charges have been proven in court.