It happened at a Bank of Montreal branch on Spadina Avenue near Dundas just before 1pm on Monday.
Police say a male suspect entered the bank wearing a mask and hood and pulled out a knife.
He allegedly then jumped over the counter, approached an employee and demanded cash.
The employee took cash from his wallet and offered it to the suspect, police say.
The suspect took the cash but then allegedly stabbed the employee several times.
The employee was then rushed to the hospital with serious injuries but is not life threatening.
Police say the suspect, meanwhile, escaped from the bank through an emergency exit at the back of the facility.
“He is considered armed, violent and dangerous,” police said in a press release issued on Thursday.
The suspect is described as Black, aged between 20 and 30 with a slender physique. He was last seen wearing a yellow toque, a red hood, a black jacket, torn blue jeans, red running shoes and a white mask. He was also carrying a black backpack.
Police are appealing to the public for help in locating the suspect.
