The man entered a Bank of Montreal branch at 2739 Eglinton Ave. E., near Danforth Road, early Monday afternoon.
Police say the suspect is a 60-something white male who has white hair and wore a yellow golf shirt. The man said he had a gun, but the teller did not see a weapon.
The man fled with cash.
Police were called to the scene at 1:21 p.m. They are searching the area for the suspect.
The Toronto area has seen a sharp decrease in the number of bank robberies over the past decade or so, mirroring a trend that has been seen across Canada.
Statistics from the Canadian Bankers Association indicate that there were 236 reported bank robberies across the Greater Toronto Area in 2000, compared to 116 in 2012.
Similarly, there were 1,098 bank robberies across Canada in 2000. Twelve years later, there were 591 reported robberies that occurred in 2012.