Hi,
I am a Canadan Citized and own a condo in Orlando, FL. Do I have to pay any taxes in US on rental income?

Yes; such rental income is consider to be "effectvely connected" to a U.S. business source and thus taxable.

It is likely that no tax will be due, because the depreciation deduction, combined with other rental expenses, will probably exceed your rental income. Even so, a federal tax return will be required.

Fortunately, no state income tax exists in Florida, so no state return will be needed.