Does a will's power of sale clause let an estate trustee sell property without going to court in Ontario?

Generally, yes, once the trustee has their Certificate of Appointment. A well-drafted will typically includes an express power of sale, giving the estate trustee broad discretion to sell estate property, including real estate, without needing to go back to court for separate approval each time. This is the normal, expected mechanism for administering an estate — the certificate confirms the trustee's overall authority, and the power of sale clause confirms they can exercise that authority to sell property as part of administering the estate.

Court involvement becomes necessary in narrower circumstances: where the will is silent or unclear about selling property, where co-trustees are deadlocked, where beneficiaries are disputing the trustee's decisions, or where a specific transaction raises a conflict of interest the trustee wants court protection for. A properly authorized sale under an ordinary power of sale clause doesn't need this extra step, but the trustee still has to exercise that power consistent with their fiduciary duty, meaning a technically authorized sale can still be challenged if it was handled unreasonably. Anyone acting as trustee should confirm the specific wording of their power of sale clause with a lawyer before assuming it covers every situation they encounter.