East of England
O
- Oak Hill, East of England
- Oakington
- Oakley, Mid Suffolk
- Oaks Tye
- Oby
- Occold
- Offord Cluny
- Offton
- Old Beetley
- Old Brigg
- Old Buckenham
- Old Catton
- Old Felixstowe
- Old Hall Street
- Old Hunstanton
- Old Hurst
- Old Lakenham
- Old Newton
- Old Walsoken
- Old Weston
- Old Wimpole
- Oldeamere
- Oldfield, Kings Lynn and West Norfolk
- Olmstead Green
- Onehouse
- Orange Row
- Orchard Park, South Cambridgeshire
- Orford, East of England
- Ormesby Common
- Ormesby St Margaret
- Ormesby St Michael
- Orwell
- Ostlers Green
- Otley (East Suffolk)
- Otley Bottom
- Otley Green
- Oulton Broad
- Oulton Street
- Ousden
- Outwell
- Over End, Huntingdonshire
- Over End, South Cambridgeshire
- Overstrand
- Overy Staithe
- Ovington, East of England
- Ovington, Breckland
- Owl End
- Owl's End
- Owl's Green
- Oxborough
- Oxborough Hythe
- Oxlode
- Oxnead
- Oxwick