Toronto police say that a male customer flagged a cab near Victoria Park and Edge Park Avenue at about 4:25 a.m.
When the cab pulled up to pick up the customer, he heard a "popping sound."
The customer fled the scene.
Police say the cab driver suffered non-life threatening injuries to his ear but has since been released from hospital.
So far, police do not have a description of the suspect.
Investigators aren’t sure if it was the customer or someone else who fired the shots.