This is quite simply a list of pubs which existed in 1961 in London, nothing particularly special, except it confirms their existence, and also their address at the time.
Do you have additional detail about any of these London pubs, their history, your own photographs of yesteryear, e.g. in the 1960s and 1970s? Please let me know.
London pub history in 1961: O
Oak, 348/350 High street, Stratford E15
Oakdale Arms, 283 Hermitage road N4
Oakley Arms, 32 Hall street EC1
Odell Arms, 41 Limerston street SW10
Odessa Arms, 53/55 Odessa road E7
Offord Arms, 388 Caledonian road N1
Oglander Tavern, 17 Oglander road SE15
Old Axe, 69 Hackney road E2
Old Basing House, 25/27 Kingsland road E2
Old Bell, 95 Fleet street EC4
Old Bell, 23 Wellington street WC2
Old Blue Last, 38 Great Eastern street EC2
Old Bucks Head, 82 Lower Thames street EC3
Old Cherry Tree Hotel, 31 Grove vale SE22
Old Chesterfield, 7 Shepherd street W1
Old Cider Stores, 4 London road SE1
Old Cock Tavern, 259 Upper street N1
Old Coffee House, 49 Beak street, Regent street W1
Old Crooked Billet, 15 Crooked Billet SW19
Old Crown, 90 Highgate hill N19
Old Crown, 33 New Oxford street WC1
Old Duke of Cambridge, 158 Devons road E3
Old Eagle, 251 Royal College street NW1
Old England, 37 Delamere crescent W2
Old Farm House, 40 Doddington road SW11
Old Farm House, 291 Kentish town road NW5
Old Father Thames, 11 Albert embankment SE11
Old Fountain, 3 Baldwin street, City road EC1
Old Friend, 129 Roman road E2
Old Friends, 11/15 Woolwich road SE10
Old George, 379 Bethnal green road E2
Old George, 40 Mortlake High street SW14
Old Gipsy House, 69 Gipsy road SE27
Old Globe, 191 Mile end road E1
Old Hall Tavern, Hall lane E4
Old Hat, 128 The Broadway, West Ealing W13
Old Horns, 68 Warner place E2
Old House, 45 Plough road SW11
Old House at Home, 87/89 Waltney street E1
Old Ivy House, 166 Goswell road EC1
Old Ivy House, 32 Hertford road N
Old Justice, 94 Bermondsey wall east SE16
Old King Johns Head, 90 Whiston road E2
Old King of Prussia, 363 Regents park road N3
Old Kings Head, 18 Bear street WC2
Old Kings Head, 173 Blackfriars road SE1
Old Kings Head, 382 Holloway road N7
Old Kings Head, 28 Holywell row EC2
Old Kings Head, 28 Upper Clapton road E5
Old Kings Head & Mermaid, 116 Lower Thames street EC3
Old Leather Bottle, 1 Greville street EC1
Old Loyal Britons, 62 Thames street SE10
Old Manor House, 56 Bush road SE8
Old Mermaid, 364 Mare street E8
Old Mill, Old Mill road SE18
Old Miller of Mansfield, 82 Snowsfields SE1
Old Nuns Head, 15 Nunhead green SE15
Old Oak, 1 Mansfield road NW3
Old Oak, 180 North End road W14
Old Pack Horse, 434 Chiswick High road W4
Old Parrs Head, 120 Blythe road W14
Old Parrs Head, 66 Cross street N1
Old Pied Bull, 188 Holloway road N7
Old Plough, 19 Kilburn lane W10
Old Queens Head, 44 Essex road N1
Old Queens Head, 117 London road SE1
Old Queens Head, 133 Stockwell road SW9
Old Red House, 133 Battersea park road SW11
Old Red Lion, 72 High Holborn WC1
Old Red Lion, 42 Kennington park road SE11
Old Red Lion, 418 St, John street EC1
Old Red Lion, 217 Whitechapel road E1
Old Rising Sun, 79 Marylebone High street W1
Old Rose, 128 The Highway E1
Old Rose, 22 & 23 Medway street SW1
Old Rose Inn, 272 New Cross road SE14
Old Sergeant, 104 Garratt lane SW18
Old Seven Sisters, Markfield road N15
Old Ship, 2 Sylvester path E8
Old Ship, 25 Upper Mall W6
Old Spotted Dog Hotel, Neasden lane NW10
Old Star, 14 Watts street E1
Old Star & Crown, 66 Broadway SW1
Old Swan, 116 Battersea Church road SW11
Old Three Colts, 450 Old Ford road E3
Old Tigers Head, 351 Lee High road SE12
Old Welsh Harp, The Broadway, West Hendon NW9
Old White Horse, 20 Peckham rye SEl5
Old White Horse, 2 St Clements lane WC2
Old White Lion, High road N2
Old Windmill, 214 Chiswick High road W4
Old Wine House, 111/112 Whitechapel High street E1
Olde Tabard, 85 Borough High street SE1
Olive Branch, 20 Homer street, Marylebone road Wl
Olive Branch, 1 Orchard hill SE13
Olive Branch, 179 Park lane N17
Olive Branch, 158/160 Waterloo road SE1
Oliver Arms 1 Bourne terrace W2
Oliver Twist, 90 Church road E10
Omnibus & Horses, 107 Harrow road W2
One Tun, 58/60 Goodge street Wl
One Tun, 125 Saffron hill EC1
Opera Tavern, 23 Catherine street, Strand WC2
Oporto Tavern, 43 West India dock road E14
Orange, 37/39 Pimlico road SW1
Orange Tree, 234 Euston road NW1
Orange Tree, 2 Friern Barnet lane N11
Orange Tree, 5 Havil street SE5
Orange Tree 18 Highfield road N21
Orange Tree, 32 & 34 Hillside NW10
Orange Tree, Totteridge lane N20
Orchard Tavern, 136 Askew road W12
Ordell Arms, 22 Ordell road E3
Ordnance Arms, 110 Barking road E16
Ordnance Arms, 18 Beresford sq SE18
Ordnance Arms, 29 Ordnance hill NW8
Ordnance Arms, 75 York road SE1
Original Woodman, 42 & 44 Battersea High street SW11
Osborne Arms, 139 Church road E10
Osborne Arms 14 New King street SE8
Osidge Arms, Hampden square N14
Ossory Arms, 47 Ossory road SE1
Owl, Silver street N18
Ox & Gate, Oxgate lane NW2
Oxford, 75 Bridport place N1
Oxford Arms, 265 Camden High street NW1
Oxford Arms, 65 Clapham park road SW4
Oxford Arms, 32 Deptford Church street SE8
Oxford Arms, 21 Halliford street N1
Oxford Arms Naseby road SE19
Oxford Arms, 43 Stepney way E1
Oxford Arms, 14 Westminster bridge road SE1
Oxford & Cambridge, 70 Hammersmith bridge road W6
Oxford & Cambridge, 2 New Oxford street WC1
Oxford Tavern, 256 Kentish town road NW5