- Nun Court
- Nunnery Court
- Oak Tree
- Oakey Street
- Oakley's Yard
- Oakey's Yard in Boyle
- Oaklyes Court, Yard
- Oat Lane
- Oate Lane, Billingsgate
- Offele Alley
- Officiality of London
- Okebourn
- (St.) Olave at Crutched Friars
- (St.) Olave Bradestrat
- (St.) Olave Bread Street Hill
- (St.) Olave by London Bridge
- (St.) Olave by the Tower or versus Turrim
- (St.) Olave de Cripelesgate
- (St.) Olave Eldiurie
- (St.) Olave Hart Street
- (St.) Olave in Colchirch Lane
- (St.) Olave in the Shamb1es
- (St.) Olave Jewry
- (St.) Olave Mogwell Street, de Mugwellestrate
- (St.) Olave near Martelane
- (St.) Olave next Dowgate
- (St.) Olave Old Jewry
- (St.) Olave Silver Street
- (St.) Olave Silver Street Churchyard
- (St.) Olave towards Alegate
- (St.) Olave without Bishopsgate
- Old Artillery Ground
- The Old Bailey
- Old Bedlam Court
- Old Bedlam Lane
- Old Bell Inn
- Old Bethlehem Hospital
- Old Bethlem
- Old Bethlem, Street
- Old Brewers Yard
- Old Brewhouse Yard
- Old Broad Street
- Old Change
- Old Change Hill
- Old City Chambers
- Old Dean's Lane
- Old Dog
- Old Exchange
- Old Fish Market
- Old Fish Street
- Old Fish Street Hill
- Old General Post Office
- Old Horseshoe Wharf
- Old Jewry
- Old Jewry Chambers
- Old Lane
- Old Ludgate
- Old Navy Office
- Old Pipe Yard
- Old Piscaria
- Old Place
- Old Sergeants' Inn, Chancery Lane
- Old Shades Wharf
- Old South Sea House
- The Old Swan
- Old Swan Alley
- Old Swan Lane
- Old Swan Pier
- Old Swan Stairs
- Old Swan Wharf
- Old Temple
- Old Temple, Bar of
- Old Trinity House
- Old Victualling Office
- Old Wardrobe
- Old Watch House, Bishopsgate
- Old Wool Quay
- Old Yard
- Olde Hall
- Olde Swanne Alley
- Olivaunt
- Olive Court, St. Katherine's
- Oliver's Court
- Olvendebrigge
- One Swan Yard
- One Tun Yard
- Oram's Court
- Orance Court
- Ormond Place
- Le Osyer Yarde
- (St.) Osyth
- Owyn Win Newgate
- Oxenden Corner
- (Earl of) Oxford, Hostel of
- Oxford Armes Inn
- Oxford Arms Inn
- Oxford Arms Passage
- Oxford Arms, Oxford Arms Inn
- Oxford Court
- Oxford Court, Camomile Street