- The Optoelectronics Company - Green End Farm, Bishops Stortford, Hertfordshire, CM22 6AY
- The Optoplast Actman - Cobb House, 2-4 Oyster Lane, West Byfleet, Surrey, KT14 7DU
- The Original Gauge Company - Unit4 Nova Business Park, New Milton, Hampshire, BH25 6SA
- The Original Wordsmith - Rambledown, Cranleigh, Surrey, GU6 7QP
- The Orthodontic Clinic - 9 Golden Square, Aberdeen, Aberdeenshire, AB10 1RB
- The Osprey Company - Guards Road, Coldstream, Berwickshire, TD12 4EE
- The Owl - Unit 9 Grafton Way, Basingstoke, Hampshire, RG22 6HY
- The Oxford Partnership - Oxford - Lancelyn House, Oxford, Oxfordshire, OX2 6ew
- The Oxfordshire Stove Company Ltd - Royal Oak Farm, Islip Road, Oxford, Oxfordshire, OX14 4EZ
- The P.P. Group of Companies - Profiles Point, Oldham, Greater Manchester, OL9 7PH
- The Packaging Company - 195 Scudamore Road, Leicester, Leicestershire, LE3 1UQ
- The Packaging Experts - Unit 1, Argent House, Basingstoke, Hampshire, RG24 8NS
- The Packaging Federation - 1 Warwick Row, London, SW1E 5ER
- The Pallet Supply Co Ltd - BP Fuel Site, Beds, LU6 1NE
- The Palm Centrre - Ham Central Nursery, Richmond, TW10 7HA
Companies 1951 to 1965 | Page 131 of 273