Are stepchildren automatically entitled to inherit from a stepparent who dies without a will in Ontario?

No. Stepchildren are not included in Ontario's intestacy hierarchy unless they have been legally adopted by the stepparent. Ontario's Succession Law Reform Act defines "child" for intestacy purposes as a biological child or a legally adopted child — a stepchild who was not adopted has no automatic right to inherit under intestacy.

This is a common source of disappointment in blended families. A stepparent may have played a central role in raising a child for many years, but without adoption or a will that names the stepchild, that child receives nothing from the stepparent's intestate estate. The estate would instead pass to the stepparent's biological children, legal adoptees, or other relatives as per the hierarchy.

A will is the essential tool for including stepchildren in your estate plan. You can make specific gifts, include them as residuary beneficiaries, or even set up trusts for them. A stepchild who was financially dependent on the deceased may also have standing to bring a dependant's support claim, regardless of whether they are in the intestacy hierarchy.