| Primary Designs Limited | Manufacturing | 1998 |
| Pritchard-Jeffs Limited | Professional & scientific | 2003 |
| Pro Prop Solutions Limited | Real estate | 2021 |
| Product Ascent Ltd | Professional & scientific | 2024 |
| Production Management Services Ltd | Information & communication | 2012 |
| Project Ford Limited | Real estate | 2023 |
| Proton Energy Limited | Professional & scientific | 2025 |
| Prov AV Limited | Administrative & support | 2025 |
| Pullen and Pike Bespoke Kitchens and Interiors Ltd | Manufacturing | 2011 |
| Purple Orange Consultants Limited | Professional & scientific | 2008 |
| PUSHP4Y Ltd | Professional & scientific | 2021 |
| PVM Technology Limited | Professional & scientific | 2023 |
| Q-Branch Limited | Information & communication | 2007 |
| Qdot Technology Ltd | Professional & scientific | 2018 |
| Qenconsult Ltd | Professional & scientific | 2016 |
| Qmda Limited | Professional & scientific | 2017 |
| Qronos Limited | Health & social care | 2023 |
| Quantistruct Limited | Construction | 2024 |
| Quantum Reactivity Ltd | Professional & scientific | 2026 |
| Quantum Response Network Limited | Administrative & support | 2015 |
| Quartermain Court Limited | Households | 2023 |
| Quench Cryogenics Limited | Professional & scientific | 2010 |
| Quick Kitchens Ltd | Administrative & support | 2022 |
| Qutis Limited | Health & social care | 2010 |
| Qutis Medico Beauty Limited | Health & social care | 2014 |
| Qutis Trustees Limited | Professional & scientific | 2025 |
| Qutis Witney Limited | Health & social care | 2012 |
| R & E Jarman Limited | Hospitality | 2015 |
| R & R Developments (Oxon) Ltd | Construction | 2015 |
| R G Drylining Ltd | Construction | 2024 |
| R H Homes (Project 5) Limited | Real estate | 2016 |
| R.C.H. Services Limited | Construction | 1997 |
| R.J. Pykett Building Services Limited | Construction | 2002 |
| R.J.A Cables Limited | Manufacturing | 2024 |
| Rachel Harris Professional Tutoring Ltd | Education | 2021 |
| Racketware Limited | Information & communication | 2009 |
| Radio Star Rentals Ltd | Administrative & support | 2025 |
| Radius Management & Logistics UK Limited | Transport & logistics | 2003 |
| Rainman Projects Ltd | Professional & scientific | 2014 |
| Raman Group Limited | Manufacturing | 2025 |
| Raptor Couplers Ltd | Manufacturing | 2021 |
| Raven Worldwide Ltd | Information & communication | 2008 |
| Ray-Ran Test Equipment Limited | Manufacturing | 1983 |
| RB Property Search Ltd | Real estate | 2025 |
| RCP Service Centre Limited | Wholesale & retail | 2000 |
| Re-Forme Studio Limited | Arts & recreation | 2025 |
| Reading Creative Ltd | Professional & scientific | 2020 |
| READY4MORTGAGE Ltd | Professional & scientific | 2026 |
| Real Innovations Ltd. | Real estate | 2005 |
| Real Living Guildford Limited | Financial services | 2025 |
| Real Living Limited | Real estate | 2023 |
| Reaston Brown Estate Agents Limited | Real estate | 1998 |
| Reaston Brown Rentals Limited | Real estate | 1998 |
| Rebecca Davies Health Limited | Health & social care | 2021 |
| Red FOX Studio Limited | Professional & scientific | 2014 |
| Regler and Company (Chinnor) Limited | Professional & scientific | 2016 |
| Regtech Data Ltd | Information & communication | 2021 |
| Relode Energy Limited | Professional & scientific | 2024 |
| Rennie Logistics Ltd | Administrative & support | 2024 |
| Rerooted Ltd | Professional & scientific | 2023 |
| Resident Dogs Ltd. | Real estate | 2000 |
| Response BA Limited | Information & communication | 2025 |
| RFT Group Ltd | Information & communication | 2013 |
| RG & TG Properties Ltd | Real estate | 2009 |
| RGM Accountancy & Taxation Services Limited | Professional & scientific | 2006 |
| RGS Limited | Manufacturing | 1994 |
| Rhubarb Seating Limited | Manufacturing | 2011 |
| Ricey Ltd | Professional & scientific | 2023 |
| Richard & Emily Jarman LLP | | 2015 |
| Ridgeway PUB Company Limited | Hospitality | 2010 |
| Rigreen Properties Ltd | Real estate | 2024 |
| Ripe NOW Limited | Wholesale & retail | 2006 |
| Ripe NOW Property Ltd | Real estate | 2018 |
| Rival Strategy Limited | Administrative & support | 2016 |
| RJ Wood Consulting Ltd | Other services | 2024 |
| Robarts Farming Limited | Agriculture & fishing | 2023 |
| Robero Consulting Ltd | Information & communication | 2018 |
| Robert Brown Steel Structures Limited | | 1981 |
| Roch Lighting Solutions Limited | Wholesale & retail | 2019 |
| ROE Communications Limited | Professional & scientific | 2016 |
| Roll UP and Rock Ltd | Professional & scientific | 2014 |
| Roller Door Expert Ltd | Manufacturing | 2015 |
| Roller Shutter Expert Ltd | Manufacturing | 2015 |
| Rooks Lane Residents' Association Limited | Households | 2003 |
| Root Solutions Tree Care Ltd | Administrative & support | 2025 |
| Roots With Miles Ltd | Administrative & support | 2025 |
| Rosacom Ltd | Information & communication | 2020 |
| Rose Flooring and Wholesale Limited | Construction | 2018 |
| Rosemary Street Health Limited | Health & social care | 2011 |
| Rosie’S Hideaway Ltd | Hospitality | 2025 |
| Ross Plaskow Ltd | Professional & scientific | 2022 |
| Royd Audio Ltd | Information & communication | 1983 |
| RS Recruitment Solutions Limited | Administrative & support | 2000 |
| RTJ Enterprises Limited | Real estate | 2020 |
| Rubicon Drones Limited | Professional & scientific | 2022 |
| Rudman Renewables Ltd | Construction | 2024 |
| Rufilla Ltd | Information & communication | 2009 |
| Rural Technology Ltd | Administrative & support | 2013 |
| Rushair Limited | Administrative & support | 2012 |
| Russ Mansford Associates Limited | Professional & scientific | 2012 |