In the absence of a Will, do de facto spouses, who lived together for several years, have the right to inherit property of the deceased de facto spouse?

No, in this case, de facto spouses do not have the same rights as married or civil union spouses. The Civil Code of Quebec grants to the survivor no rights in the property of the deceased de facto spouse. This means that, no matter the number of years of common live, the surviving de facto spouse can inherit the property of the deceased de facto spouse only if a Will was made in his favor.