some insurance companies will insure your property as a standalone rental under a commercial policy.
rental property insurance in Ontario can also be done under a personal lines policy when you have your primary residence insured with them as well. But there are restrictions which vary from company to company. For instance, the number of units in the home can usually not exceed 2 or 3. By units, I mean separate kitchens and bathrooms with no sharing between units, and just 1 family living within each unit. Although there is a company that can do a six plex + the primary residence, but they won't add anymore rentals after 6 units is reached. Another restriction includes the number of rental properties, most will allow 3 or 4 rental properties (plus your home) on one policy, I do know of one that can do over 20. Under a personal policy, chances are you could qualify for a multiline discount when you add your car insurance with that company as well. Other restrictions are there but vary from company to company. For the small to medium sized landlord in Ontario looking for insurance for their home and 3 rental properties with 1 family living in each, having them insured under a personal lines policy might be a better choice.
For those that own student rental houses, i.e rooming houses, a commercial policy is what you need (I am not aware of any companies that will insure them under personal lines) and it is important that you look on the policy that the description states it is being tenated as a student rental.
I kept things very general, it is best to speak to a licensed insurance representative about your situation, as every situation is unique.