What happens to leasehold improvements I paid for when my Ontario commercial lease ends?

It depends entirely on what the lease says, since there's no single default answer that applies to every commercial lease in Ontario. Leasehold improvements a tenant installs, such as built-in fixtures, flooring, or custom millwork, generally become part of the real property once installed, meaning they typically stay with the landlord's building unless the lease specifically says otherwise, but well-drafted commercial leases almost always address this directly rather than leaving it to that general default.

Many leases require the tenant to remove specified improvements and restore the space to its original or "base building" condition at the end of the term, at the tenant's own expense, while others allow improvements to simply remain for the landlord's benefit with no restoration obligation, or draw a line between different categories of improvements. Some leases combine both: certain fixtures may stay, while others, like custom signage or specialty equipment installations, must be removed.

Because this can mean the difference between walking away and facing a significant restoration bill at lease-end, tenants making a substantial investment in build-out should clarify and negotiate this specific point before signing, not assume it will sort itself out later.