Do half-siblings inherit under Ontario's intestacy rules?

Yes, half-siblings can inherit under Ontario's intestacy rules, but how they share depends on whether full siblings also survive. Under the Succession Law Reform Act, if the deceased left both full siblings and half-siblings, a half-sibling inherits half as much as a full sibling. This reflects the fact that a half-sibling shares only one parent with the deceased.

If only half-siblings survive (and no full siblings), they inherit equally, as there is no full sibling to compare. The half-sibling provision only reduces a half-sibling's share relative to full siblings when both categories are present.

This rule can produce surprising results in blended families where some children share both parents with the deceased and others share only one. It is worth understanding how this formula would apply to your own family, since a will can override these default rules entirely and allow you to treat all siblings equally — or differently — as you choose.