Do stepchildren automatically inherit in Ontario if my will does not mention them?

No. In Ontario, stepchildren have no automatic inheritance rights. Under both the intestacy rules (if you die without a will) and general estate law, "children" means biological or legally adopted children. A stepchild who has not been formally adopted by you is not treated as your child for inheritance purposes unless your will explicitly includes them.

This often surprises blended families who assume that years of living together and parenting create legal rights. They do not, at least not for inheritance. If you want a stepchild to inherit, you must say so clearly in your will. You can name a stepchild as a beneficiary, leave them a specific gift, or include them in a residuary bequest.

Formal adoption of a stepchild does create full inheritance rights, just as with a biological child. Once adopted, a stepchild is treated as your child in law for all purposes, including intestacy and entitlement under a will that gifts to "my children."

If you have stepchildren and want them to benefit from your estate, review your will carefully with a lawyer. The wording matters — a gift to "my children" will typically not include stepchildren unless the will defines "children" to include them.