- 4.8Closed nowOk Ok Diner1128 Queen Street East, Toronto, ON M4M 1K9Restaurant
- 4.4Closed nowOld Man Pizza223 Jameson Avenue, Toronto, ON M6K 2Y3Restaurant
- 3.2Old Mill Toronto21 Old Mill Road, Etobicoke, Toronto, ON M8X 1G5Restaurant Bar Night club
- 4.6Closed nowOld Sod Restaurant2936 Bloor Street West, Etobicoke, Toronto, ON M8X 1B5Restaurant Bar
- 4.6Closed nowOld York Bar Grill167 Niagara Street, Toronto, ON M5V 1G8Restaurant Bar
- 4.6Closed nowOlde Stone Cottage Pub3750 Kingston Road, Scarborough, Toronto, ON M1J 3H5Restaurant Bar
- 4.8Closed nowOlde Yorke Fish & Chips96 Laird Drive, East York, Toronto, ON M4G 3V2Restaurant
- 3.2Closed nowOlio801 Dixon Road, Etobicoke, Toronto, ON M9W 1J5Restaurant
- 2.8Closed nowOliver & Bonacini Café Grill2901 Bayview Avenue, North York, Toronto, ON M2N 5Z7Restaurant
- 3Closed nowOliver & Bonacini Café Grill, Yonge & Front33 Yonge Street, Toronto, ON M5E 1G4Restaurant Bar
- 4.4Closed nowOm Restaurant1439 Queen Street West, Toronto, ON M6R 1A1Restaurant
- 3.8Closed nowOmi Sushi4352 Kingston Road, Scarborough, Toronto, ON M1E 2M8Restaurant
- 3.8Closed nowOn The Rocks Restaurant & Karaoke Bar169 Front Street East, Toronto, ON M5A 3Z4Restaurant Bar Night club
- One171 East Liberty Street, Toronto, ON M6K 3P6Restaurant
- 3.4One King West Hotel & Residence1 King Street West, Toronto, ON M5H 1A1Restaurant Bar
- Closed nowOne Love Media1850 Albion Road, Etobicoke, Toronto, ON M9W 5T2Restaurant
- 3.4Closed nowOne Restaurant116 Yorkville Avenue, Toronto, ON M5R 1C2Restaurant
- 4.6Closed nowOne2Snacks8 Glen Watford Drive #26, Scarborough, Toronto, ON M1S 2B7Restaurant
- 4.6Onoir620 Church Street, Toronto, ON M4Y 2G2Restaurant
- Ontario Catering Club601 Milner Av, Scarborough, Toronto, ON M1B 1M8Restaurant
- Orchid Café655 Dixon Road, Etobicoke, Toronto, ON M9W 1J3Restaurant
- 3.8Closed nowOrfus wrap and grill3240 Dufferin Street, North York, Toronto, ON M6A 2T3Restaurant
- 4.6Closed nowOriental Taste329 Queen Street East, Toronto, ON M5A 1S9Restaurant
- 3.6Closed nowOriginals Ale House1660 Bayview Avenue, Toronto, ON M4G 3C2Restaurant Bar