Police described the incident as “vicious and violent” in a statement.
The attack occurred on Tuesday around 10:45 p.m at the Square One bus terminal.
The 29-year-old victim was sitting on the stairs when three male suspects approached him, punching and kicking him several times within only 10 seconds.
Police said in a statement the victim was taken to a local hospital with serious but non-life-threatening injuries.
Eyewitnesses urged to call police
All three suspects were described as South Asian males, about five feet and 10 inches tall, according to Peel Police.
The first suspect was with a light complexion and thin build. The man had a dark short beard and straight black hair above the ears. He wore a black T-shirt with a red Air Jordan logo and white Jordan lettering, with black track pants and black shoes.
The second suspect had a thin build and was clean shaven. He wore a black jacket with a grey horizontal stripe across the chest and a grey vertical stripe along the hood, black track pants and black shoes.
The third suspect had a medium build and was unshaven. The man wore a black hoodie with a Nike logo on the front, white Nike lettering along the sleeves, black track pants and black shoes.
Toronto Mayor John Tory was among those asking for information on Twitter.
Police are asking anyone with information to contact investigators at the 12 Division criminal investigation bureau at (905) 453-2121, ext. 1233.
Any information may be left anonymously by calling Peel Crime Stoppers at 1-800-222-TIPS (8477) or visiting website, or by sending a text message to CRIMES (274637) with the word ‘PEEL’ and then a tip.