- The Office Way - 64 Derby Road, Long Eaton, Nottinghamshire, NG10 4QP
- The Oil Lab Ltd - 15 Limefield, Blackburn, Lancashire, BB2 6PJ
- The Old Byre Visitor Centre - Auchencar Farm, Isle of Arran, Scottish Islands, KA27 8EB
- The Old Forge Ltd - La Route D'ebenezer, Jersey, Channel Islands, JE3 5DS
- The Old Pump House - The Old Pump House, St. Ives, Cornwall, TR26 3EU
- The Old Well Garden Centre - Waterloo Cross, Cullompton, Devon, EX15 3ES
- The Olympia Beauty Show - 1 The Courtyard, Westerham, Kent, TN16 1AZ
- The Olympic Varnish Company Ltd - Val D'or Works, Knapp Lane, Stroud, Gloucestershire, GL5 2TQ
- The One Stop Embroidery & Printing Co - Elmbank Road, Walsall, West Midlands, WS5 4EL
- The Only Way is Granite Ltd - Unit 6 Pilot Close, Fulmar Way, Wickford, Essex, SS11 8YW
- The Open Group - Apex Plaza, Reading, Berkshire, RG1 1AX
- 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
Companies 1921 to 1935 | Page 129 of 272