Southwark Business by letter: o
- O D S Optical Disc Service Ltd, Southwark
- O D T Europe Ltd, Southwark
- O M Retail, Southwark
- O O Sangowawa, Southwark
- O W Loeb & Co Ltd, Southwark
- O'Carroll Rooney, Southwark
- O'Connor Design, Southwark
- O'Sullivan Concept Salons, Southwark
- Oak Carpenter Contractors (London), Southwark
- Oak Tree Nursery, Southwark
- Oak Tree Nursery, United Reformed Church, Southwark
- Oaklands Refugee Services, Southwark
- Oakwoods Joinery Ltd, Southwark
- Oasis, Southwark
- Oasis Health Centre, Southwark
- Oasis Trust, Southwark
- Obayashi Corporation, Southwark
- Obis 360, Southwark
- Oblong Productions, Southwark
- Obsessions, Southwark
- Ocean Blue, Southwark
- Ocean View Landscapes, Southwark
- Octopus Digital Display Ltd, Southwark
- Oddbins Ltd, Southwark
- Oddbins Ltd, Southwark
- Odessa Wharf, Southwark
- Odie & Amanda, Southwark
- Odiyan African Store, Southwark
- Odyssey Assett Management Systems Ltd, Southwark
- Ofcom, Southwark
- Office Angels, Southwark
- Office Design Partnership, Southwark
- Office Link Installations Ltd, Southwark
- Office Of Communications, Southwark
- Office On Spec, Southwark
- Office World, Southwark
- Ogilvie & Oliver, Southwark
- OISC, Southwark
- Old Alleynian Rugby Football & Cricket Club, Southwark
- Old College Lawn Tennis & Croquet Club, Southwark
- Old Justice, Southwark
- Old Kent, Southwark
- Old Kent Cars, Southwark
- Old Kent Road Car Breakers, Southwark
- Old Kent Road Post Office, Southwark
- Old Nuns Head, Southwark
- Olive, Southwark
- Olive 360 Ltd, Southwark
- Oliver Ashley, Southwark
- Oliver Burn Ltd, Southwark
- Oliver Goldsmith Primary School, Southwark
- Oliver Jaques, Southwark
- Oliver Jaques Ltd, Southwark
- Oliver Tree Kebab Shop, Southwark
- Olley's, Southwark
- Olley's Fish Experience, Southwark
- Olleys, Southwark
- Olu' Hair Stylist, Southwark
- Omega Property Services, Southwark
- Omega Services, Southwark
- Omers Cafe, Southwark
- Omila Business Services, Southwark
- On The Move Removals, Southwark
- On Time Print & Design Ltd, Southwark
- On Your Bike Holding Ltd, Southwark
- One For The Road, Southwark
- One Love International, Southwark
- One Up Display Service, Southwark
- Onebravo, Southwark
- Open City, Southwark
- Open Door Housing Trust, Southwark
- Opendoor Housing Trust, Southwark
- Opendoor Housing Trust, Southwark
- Operandi, Southwark
- Oppida Ltd, Southwark
- Optical Marketing Ltd, Southwark
- Optika, Southwark
- Optim Contract Services, Southwark
- Optim Contract Services Ltd, Southwark
- Option2, Southwark
- Options, Southwark
- Optomen Televison, Southwark
- Oralon Dental Clinic, Southwark
- Orbit Housing Association, Southwark
- Orca Media Ltd, Southwark
- Oriella's Sandwich Bar, Southwark
- Orient Espresso, Southwark
- Oriental Culture, Southwark
- Oriental Kitchen, Southwark
- Oriental Motor Repairs, Southwark
- Oriental Noodle Hut, Southwark
- Orion, Southwark
- Osborn & Simmons Ltd, Southwark
- Osbourne Stewart, Southwark
- Osibanjo & Co, Southwark
- Oskat, Southwark
- Oskat Finance & Investment Services, Southwark
- Otis Ltd, Southwark
- Our Baby, Southwark
- Our Graphics Ltd, Southwark
- Our Lady Of La Salette R C Church, Southwark
- Our Lady Of Sorrows R C Church, Southwark
- Our Precious One, Southwark
- Outer Sanctum, Southwark
- Outline, Southwark
- Output Communicators, Southwark
- Oval Workshop, Southwark
- Ovenu, Southwark
- Overdrive Design, Southwark
- Overseas Courier Service (London) Ltd, Southwark
- Owen H R PLC, Southwark
- Owens' Dental Practice, Southwark
- Owoyele Dada & Co Solicitors, Southwark
- Oxbridge Capital Ltd, Southwark
- Oxbridge Information Brokers, Southwark
- Oxo Hairdressing Ltd, Southwark
- Oxo Tower, Southwark
- Oxo Tower Wharf, Southwark
- Oyez Co Services, Southwark
- Oyez Straker, Southwark
- Oyez Straker Office Supplies Ltd, Southwark
- Ozzies, Southwark