The incident unfolded around 11:30 p.m. in the Finch Avenue West and Dufferin Street area. That's when paramedics say a man in his 20s was stabbed.
Police say the suspect is a white man who is believed to be standing five feet, nine inches tall. He wasn't wearing a shirt at the time of the stabbing, police added.
Anyone with information about the suspect's whereabouts is asked to call 911 immediately. Police say the suspect should not be approached.