Peel Regional Police said an altercation took place at 6:30 p.m. on July 28 around Steeles Avenue West and Chinguacousy Road.
The suspect and victim — who police do not think knew each other — got into an argument. Police said that led to the man stabbing the victim several times.
The victim was taken to hospital with non-life-threatening injuries.
The suspect is outstanding. Police said he had a slim build and wore a blue t-shirt, dark jeans, black shoes and a black baseball cap. He also had a black backpack, investigators said.