Madrid Airport Car Hire

In the event that a driver's license is issued in a country that is not a party to the international convention on road traffic, an official translation must be attached to them. When renting within the EU, customers from countries outside the EU must also present an international driving license.

So yes, you will need a IDL to drive your renal car in Spain. You can find thid information under "IMPORTANT INFORMATION" at the right hand side of each car photo. Click on it and then click on "DRIVER"

You will see the next information:- When renting within the EU, customers who do not hold a driving licence issued by an EU/EEA country or Switzerland must also present an International Driving Permit along with their domestic licence.

Anyway you will need to have an IDL when you want to rent a car in Spain as a Canadian citizen.