- Oakhurst to Quest Castle Hill
- Oakville to Quest Castle Hill
- Oatlands to Quest Castle Hill
- Oatley to Quest Castle Hill
- Old Guildford to Quest Castle Hill
- Old Toongabbie to Quest Castle Hill
- Oran Park to Quest Castle Hill
- Orchard Hills to Quest Castle Hill
- Oxford Falls to Quest Castle Hill
- Oxley Park to Quest Castle Hill
- Oyster Bay to Quest Castle Hill
- Sydney Airport to Quest Castle Hill
- Quest Castle Hill to Oakhurst
- Quest Castle Hill to Oakville
- Quest Castle Hill to Oatlands
- Quest Castle Hill to Oatley
- Quest Castle Hill to Old Guildford
- Quest Castle Hill to Old Toongabbie
- Quest Castle Hill to Oran Park
- Quest Castle Hill to Orchard Hills
- Quest Castle Hill to Oxford Falls
- Quest Castle Hill to Oxley Park
- Quest Castle Hill to Oyster Bay
- Quest Castle Hill to Sydney Airport