The incident took place at the CIBC at the corner of Gardiners Road at Taylor Kidd Boulevard.
Det. Sgt. Jay Finn says a suspect approached two tellers, jumped over the bank counter and threatened them with a gun at 12:30 p.m.
The suspect then made off with an undisclosed amount of cash, fleeing east on Taylor Kidd Boulevard in a Toyota Crossover, according to Finn.
Kingston police described the suspect as a Black man wearing a black Canada Goose coat. They say he is still at large.