From Littlestead Green, Oxfordshire to all cities in Greater London starting with letter O
- Oakleigh Park, Oxfordshire
- Oakwood, Oxfordshire
- Old Bexley, Oxfordshire
- Old Coulsdon, Oxfordshire
- Old Ford, Oxfordshire
- Old Malden, Oxfordshire
- Old Oak Common, Oxfordshire
- Orpington, Oxfordshire
- Osidge, Oxfordshire
- Osterley, Oxfordshire