Does an executor from another country need an Ontario ancillary grant to deal with Ontario property?

Usually, yes. Where someone has already been confirmed as executor under another country's process, but the deceased also owned property in Ontario, Ontario generally still expects its own form of recognition before local institutions — banks, the land registry, investment firms — will treat that person as having authority here. That typically means applying in Ontario for recognition tied specifically to the Ontario assets, rather than relying solely on the foreign appointment.

This exists because Ontario's own asset holders and its land registration system are built around Ontario's Certificate of Appointment of Estate Trustee process; a foreign court's order doesn't automatically carry legal weight here on its own. The Ontario step is generally narrower than a full fresh probate application, since much of the underlying question, who should administer the estate, has already been decided elsewhere, but Ontario still needs its own paperwork in place before property here can be dealt with.

Because requirements can vary depending on the foreign jurisdiction involved and what documentation that jurisdiction issued, anyone in this situation should get Ontario estates advice early to confirm exactly what's needed to make the existing foreign appointment effective for the Ontario property.