Law Society of Ontario
| Barreau de l'Ontario | |
| Abbreviation | LSO | 
|---|---|
| Founded | 1797 | 
| Type | Law society | 
| Headquarters | Osgoode Hall, 130 Queen Street West, Toronto, Ontario, Canada | 
| Area served  | Ontario | 
| Official language  | English French | 
| Treasurer | Peter Wardle | 
| Affiliations | Federation of Law Societies of Canada | 
| Website | lso | 
| Formerly called | The Law Society of Upper Canada (1797–2018) | 
The Law Society of Ontario (LSO; French: Barreau de l'Ontario) is the law society responsible for the self-regulation of lawyers and paralegals in the Canadian province of Ontario. Founded in 1797 as the Law Society of Upper Canada (LSUC; French: Barreau du Haut-Canada), its name was changed by statute in 2018.