It happened around 3:05 p.m. at Birchmount Park Collegiate Institute near Danforth Avenue and Birchmount Road.
Police say information indicates the victim is a student at the school.
Birchmount Park Collegiate Institute was initially placed on lockdown after the stabbing, but police said around 4pm that officers were on the scene helping to “dismiss students safely”. Students were asked to reunite with their children in a school parking lot.
It is unclear if any arrests have yet been made in connection with the stabbing.
It is the second stabbing at the school so far this year. In April, a 14-year-old boy was stabbed outside Birchmount Park Collegiate shortly after students dismissed for the day. The teenager was seriously injured in the incident.
STABBING: Danforth Av + Birchmount Rd 3:07pm- At Birchmount Park Collegiate- Reports a student stabbed- School is on lockdown- Police on scene with @TorontoMedics- Urgent treatment at hospital #GO2221672^lb
— Toronto Police Operations (@TPSOperations) November 14, 2022