| Nyred Limited | Information & communication | 2018 |
| O & C Property Investments Ltd | Real estate | 2022 |
| O & D Services Ltd | Administrative & support | 2025 |
| O&G ENG Ltd | Professional & scientific | 2017 |
| O21 Ways Limited | Hospitality | 2023 |
| Oak Barrel Investments Ltd | Financial services | 2011 |
| Oak Hill Grove (Surbiton) Management Company Limited | Households | 2020 |
| Oak Ride Farm Kennels Ltd | Other services | 2018 |
| Oakapple Property Services Limited | Real estate | 2016 |
| Oakhill Financial Solutions Ltd | Financial services | 2025 |
| Oakhill Holdings Ltd | Financial services | 2024 |
| Oakhill Independent Financial Services Limited | Financial services | 1999 |
| Oakhill Management Limited | Professional & scientific | 1997 |
| Oaklands 28 Limited | Households | 2021 |
| Oaklea Consultancy Limited | Professional & scientific | 2014 |
| Oakwood Copse Management Company Limited | Households | 1995 |
| Oakwood Installations Limited | Construction | 2024 |
| Obair Management Ltd | Professional & scientific | 2017 |
| OBD Solutions Ltd | Professional & scientific | 2023 |
| Obencars Ltd | Transport & logistics | 2018 |
| Oberon Three Limited | Professional & scientific | 2021 |
| Oblong Solutions Ltd | Information & communication | 2023 |
| Obsidian & Associates Limited | Professional & scientific | 2025 |
| Obsidian GT Ltd | Transport & logistics | 2025 |
| OC Locks & Services Limited | Extraterritorial | 2026 |
| OC Locks, Fire and Security Limited | Administrative & support | 2019 |
| OC Security Limited | Administrative & support | 2026 |
| Oceanview Carbis Bay Ltd | Construction | 2018 |
| Ocelot Communications Ltd | Professional & scientific | 2022 |
| Ocho Branding Group Ltd | Manufacturing | 2019 |
| Ockenden Residents Company Limited | Households | 1970 |
| Octavian Design Ltd | Professional & scientific | 2018 |
| OCV Broadcasting Ltd | Information & communication | 2026 |
| Ocwv Limited | Real estate | 2021 |
| ODD Sock Media Ltd | Information & communication | 2017 |
| Oddline Engineering & Building Services Limited | | 1986 |
| Odetti Equestrian Ltd | Agriculture & fishing | 2025 |
| Ofes Cleaning Solutions Ltd | Administrative & support | 2026 |
| Offbeat Watches Limited | Manufacturing | 2026 |
| Offerwise Ltd | Information & communication | 2026 |
| Offload HQ Ltd | Information & communication | 2026 |
| OH My Gadget (OMG) Ltd | Financial services | 2017 |
| Ohtv Limited | Arts & recreation | 2026 |
| OJG Landscapes Ltd | Administrative & support | 2020 |
| Okapi SC Limited | Professional & scientific | 2019 |
| Okard Ltd | Construction | 2025 |
| Okka Lounge Limited | Hospitality | 2017 |
| Old Church Court Ltd | Construction | 2022 |
| Old Farmhouse Barn Ltd | Real estate | 2023 |
| Old Woking Cafe Ltd | Hospitality | 2023 |
| Old Woking Cars Ltd | Transport & logistics | 2023 |
| Olex Partners Ltd | Professional & scientific | 2019 |
| Olidon Ltd | Construction | 2024 |
| Olive Workswell Limited | Professional & scientific | 2023 |
| Oliveiras Gardening Ltd | Administrative & support | 2025 |
| Oliventine Consulting Limited | Wholesale & retail | 2026 |
| Oliver James (Woking) Ltd | Other services | 2020 |
| Oliver Rose Consulting Ltd | Professional & scientific | 2025 |
| Olivesoft Limited | Administrative & support | 2013 |
| OM SAI Homes Ltd | Real estate | 2018 |
| OMI Consulting Services Limited | Professional & scientific | 2025 |
| Omicron 8 Ltd | Wholesale & retail | 2024 |
| Omnithrive Limited | Professional & scientific | 2024 |
| Omniversed Ltd | Information & communication | 2022 |
| ON CUT Services Ltd | Manufacturing | 2021 |
| ON the Go Mobile Mechanics Ltd | Professional & scientific | 2024 |
| ON the Road Comp Ltd | Wholesale & retail | 2020 |
| ON Top Landscaping Ltd | Construction | 2025 |
| Onboard 365 Ltd | Information & communication | 2021 |
| Onboard Ltd | Administrative & support | 2018 |
| One C Digital Limited | Information & communication | 2023 |
| One of a Kind Clothing Ltd | Wholesale & retail | 2025 |
| One Point Mobile Ltd | Information & communication | 2011 |
| One Point Retail Ltd | Information & communication | 1997 |
| One Renovations Ltd | Construction | 2017 |
| One Shop for ALL Limited | Wholesale & retail | 2024 |
| ONE2SIX Limited | Administrative & support | 1999 |
| Onesixth Expeditions Ltd | Administrative & support | 2021 |
| Ongo Taxi Ltd | Transport & logistics | 2024 |
| Onslow Advisory Limited | Professional & scientific | 2020 |
| ONY Motors Limited | Wholesale & retail | 2008 |
| Onyac Consulting Ltd | Construction | 2025 |
| Onyra Flooring Ltd | Construction | 2026 |
| Oolite Developments Limited | Construction | 2014 |
| Ooshki Ltd | Wholesale & retail | 2025 |
| Opal Partnerships Limited | Real estate | 2026 |
| Opalside Ltd | Water & waste | 2024 |
| OPC House Limited | Administrative & support | 2023 |
| Openas Limited | Health & social care | 2021 |
| Opovate Ltd | Professional & scientific | 2022 |
| OPTI247 Limited | Wholesale & retail | 2017 |
| Optimised Consulting Ltd | Information & communication | 2012 |
| Optimist Investments (Global) Ltd | Real estate | 2021 |
| Optimum Accountancy Limited | Professional & scientific | 2013 |
| Optimum Engineering Solutions Ltd | Professional & scientific | 2024 |
| Option Five Development Limited | Construction | 2015 |
| Option Four Development Limited | Construction | 2015 |
| Option One Developments Ltd | Construction | 2014 |
| Option SIX Development Limited | Construction | 2015 |
| Option Two Development Ltd | Real estate | 2015 |