Do I need a driver's license to get a PPL in Canada?
It does not appear that a driver's license is required. From General information on pilot licences and permits, which details the requirements for getting various kinds of pilot licenses, there is no mention of a driver's license.

Prior to the issue of a permit or licence, an application must be submitted and the following requirements met:

proof of age and citizenship (not required if previously submitted)
proof of medical fitness;
proof of having met the knowledge requirements;
proof of having met the skill requirement;
proof of having met the experience requirement;
payment of the appropriate fees.