If a common-law relationship ends, can a partner claim a constructive trust interest in the home in Ontario?

Yes, this is one of the main ways a common-law partner who isn't on title can claim an interest in a shared home, since they don't have the automatic matrimonial home or equalization rights that apply only to married spouses. A constructive trust claim is generally based on the idea that it would be unfair, or unjustly enriching, for the titled partner to keep the full benefit of the property when the other partner made real contributions — financial or otherwise — that helped acquire, maintain, or increase the value of the home, without receiving anything in return.

Unlike a married spouse's rights, this isn't an automatic entitlement; the non-titled partner generally has to actually establish the claim, showing the nature and extent of their contributions and connecting them to the property in question, which can involve real evidentiary and legal complexity. If successful, a court can recognize the partner's interest as a share of the property itself, rather than just a debt owed to them, which can affect a pending or planned sale. Because these claims are fact-intensive and outcomes vary significantly, a common-law partner considering this kind of claim, or a titled partner facing one, should get legal advice early rather than assuming a straightforward result either way.