The Quebec Land Register (Registre foncier du Québec) is a public register that records all real-estate transactions carried out in Quebec since its creation in 1841. It is the authoritative source for determining who owns a property, who bought it from whom, and what legal rights or charges (such as mortgages or servitudes) apply to the property.
In a standard real-estate transaction, the register is updated by the notary, who is legally responsible for completing the transfer of ownership.
You can consult the Quebec Land Register at the following location: https://www.registrefoncier.gouv.qc.ca/Sirf/.