A case of the potentially lethal infectious disease was at Chaminade College School, which located at 490 Queen’s Dr., near Highway 400 and Jane Street.
The board is not disclosing if a staff member or student contracted tuberculosis.
Late last month, the school board confirmed a separate tuberculosis case at Mary Ward Catholic Secondary School in Scarborough.
A Toronto Public Health spokesperson says there is no connection between the two cases. The spokesperson said the general school population is believed to be "at low risk of exposure."