- O'Connor Street
- O'Meara Street
- Oak Park Private
- Oak Street
- Oakdale Avenue
- Oakhaven Private
- Oakland Avenue
- Oakley Avenue
- Oakvale Avenue
- Oasis Private
- Oat Straw Way
- Oblate Avenue
- Oblats Avenue
- Observatory Crescent
- Ohio Street
- Old Innes Road
- Old Lilac Lane
- Old Riverside Drive
- Old Saint Patrick Street
- Old Sunset Boulevard
- Old Town Private
- Olympia Crescent
- Onslow Crescent
- Ontario Street
- Orangeville Street
- Orchard Avenue
- Orchid Drive
- Orillia Street
- Orkney Private
- Orlando Avenue
- Orrin Avenue
- Ortona Avenue
- Orvigale Road
- Osborne Street
- Osgoode Street
- Ossington Avenue
- Othello Avenue
- Otterson Court
- Otterson Drive
- Owl Drive
- Oxbow Avenue
- Oxford Street