| Attorney General of Ontario v Mercer | |
|---|---|
 Andrew Mercer's cottage, near Bay and Wellington Streets, Toronto | |
| Court | Judicial Committee of the Privy Council |
| Full case name | Attorney General of Ontario v Andrew F. Mercer |
| Decided | July 18, 1883 |
| Citations | [1883] UKPC 42, 8 App Cas 767 |
| Case history | |
| Prior actions | Mercer v. Attorney General for Ontario, (1881) 5 SCR 538 |
| Appealed from | Supreme Court of Canada |
| Court membership | |
| Judges sitting | |
| Case opinions | |
| Decision by | The Lord Chancellor |
| Keywords | |
| Constitutional law, Crown prerogatives, escheat | |
Attorney General of Ontario v Mercer is a Canadian constitutional law decision of the Judicial Committee of the Privy Council in 1883, at that time the highest court of appeal in the British Empire, including Canada.
The issue in the case arose from the death of an individual, Andrew Mercer, without a will and without any heirs recognised by law. At common law, if an individual dies without heirs, the property in the estate vests in the Crown, called an "escheat". Both the federal government and the provincial government claimed the property, each relying on different sections of the British North America Act, 1867 (now known as the Constitution Act, 1867).
The dispute was litigated in the courts of Ontario and then the Supreme Court of Canada. The Ontario courts ruled in favour of the province, and the Supreme Court ruled in favour of the federal government. The Attorney General of Ontario, Oliver Mowat, QC, then appealed to the Judicial Committee, which held that the right of escheat fell to the provinces, not to the federal government.