| RJF Brickwork Limited | Construction | 2018 |
| Romich Limited | Information & communication | 1995 |
| RON Grant Removals Limited | Transport & logistics | 2007 |
| Rooke (Builders) Limited | Real estate | 1957 |
| Rose Building Supplies Limited | Wholesale & retail | 1957 |
| Rowan Humberstone Limited | Health & social care | 2002 |
| Rowney House Ltd | Construction | 2007 |
| Ruboplast Limited | Manufacturing | 2025 |
| Ryba Macaulay Limited | Information & communication | 1997 |
| Ryjen Electronics Ltd | Administrative & support | 2006 |
| S & W Design & Build Limited | Construction | 2006 |
| Sail Pikco Limited | Financial services | 2025 |
| Sanctuary Design Limited | Professional & scientific | 2006 |
| Sandy's Boutique & Salon Limited | Wholesale & retail | 2025 |
| Sapori E Saperi Adventures Limited | Administrative & support | 2006 |
| Sarah Herring Ltd | Professional & scientific | 2003 |
| Satchwell Builders Limited | Construction | 2007 |
| Savegreat Limited | Wholesale & retail | 1992 |
| Sawston Childcare Limited | Education | 2000 |
| Seal Management Solutions Limited | Professional & scientific | 2004 |
| Sens Horticulture Limited | Agriculture & fishing | 2004 |
| Shandrum Office Supplies Limited | Wholesale & retail | 2003 |
| Shelford Gospel Trust | Other services | 2008 |
| Sierra Zulu Aviation Limited | Administrative & support | 2000 |
| Silver Bike Limited | Real estate | 2008 |
| Site Compliance Training Limited | Education | 2024 |
| Sixtrees Limited | Wholesale & retail | 1973 |
| Smashes Properties Ltd | Real estate | 2006 |
| SMD (Cambridge) Limited | Professional & scientific | 2002 |
| SMS Property Management Limited | Real estate | 2005 |
| Sohamkebab & Pizza Ltd | Hospitality | 2025 |
| Sohnius & Perry Limited | Information & communication | 2000 |
| South Properties Limited | Real estate | 1996 |
| Southacre Park Freeholds Limited | Households | 2005 |
| Spectrum Stone Limited | Construction | 2006 |
| Speed Alloys Limited | Wholesale & retail | 1997 |
| Spike & Violet Limited | Other services | 2003 |
| Sports Huntingdon Limited | Arts & recreation | 2003 |
| ST Nicholas Place Limited | Real estate | 2025 |
| Stainless Steel Plant Limited | | 1957 |
| Stanley S.Gawthroup & Sons Limited | Wholesale & retail | 1960 |
| Starholme Limited | Professional & scientific | 2006 |
| Stazione Limited | Hospitality | 2001 |
| Sterling, Bolt and NUT Company Limited | Wholesale & retail | 1990 |
| Stetchworth and Middle Park Studs Limited | Agriculture & fishing | 2005 |
| Steve Hubbard Video Productions Limited | Information & communication | 2003 |
| Structural Insulated Panel Technologies Limited | | 2004 |
| Sturton Flats Management Company Limited | Households | 1998 |
| Sustainable Energy Marketing Limited | Professional & scientific | 2001 |
| Sustainable Resources Limited | Extraterritorial | 2003 |
| Swimbag Limited | Education | 2001 |
| Sycamore Alliance Limited | Financial services | 2000 |
| Synergy Organisational Solutions Limited | Professional & scientific | 2005 |
| T & S Property Investments Limited | Real estate | 2004 |
| T Simpson Decorating Limited | Construction | 2007 |
| T-Morph Limited | Information & communication | 2003 |
| T4 Travel Limited | Administrative & support | 1993 |
| Tamar IT Limited | Information & communication | 2002 |
| TAU Developments Limited | Wholesale & retail | 2002 |
| Temur Ltd | Hospitality | 2017 |
| Tente Castors Limited | Wholesale & retail | 1972 |
| Terry's Heel Bar Limited | Other services | 2003 |
| THE Admiral Wells Ltd | Hospitality | 2007 |
| THE British Skewbald and Piebald Association | Arts & recreation | 1998 |
| THE Cambridge Arts Theatre Trust Limited | Arts & recreation | 1998 |
| THE Cambridge Crystallographic Data Centre | Professional & scientific | 1987 |
| THE Collection LAB Ltd | Professional & scientific | 2025 |
| THE Cottenham Old Dairy Management Company Limited | Households | 1994 |
| THE Garden Bench Company Limited | Wholesale & retail | 2007 |
| THE Hemingford Sports Academy Community Interest Company | Arts & recreation | 2016 |
| THE Jolly Fryer Limited | Hospitality | 2003 |
| THE Millington Road Nursery School Trust | Education | 2005 |
| THE Old Stock Yard Management Company Limited | Households | 1993 |
| THE Plain Truth | Information & communication | 2002 |
| THE Psychology Service - Therapy Division Limited | Health & social care | 2001 |
| THE Quara Group Limited | Financial services | 2022 |
| THE Spinal Physiotherapy & Sports Medicine Clinic Ltd | Health & social care | 2006 |
| THE Sunflower House Limited | Hospitality | 2020 |
| THE Three Kings (Haddenham) Ltd | Hospitality | 2004 |
| Theclickshop Ltd | Wholesale & retail | 2022 |
| Thinking About Crime Limited | Professional & scientific | 2003 |
| Thurlby Thandar Instruments Limited | Manufacturing | 1989 |
| Thurlow Nunn (Holdings) Limited | Real estate | 1951 |
| Thurlow Nunn Limited | Wholesale & retail | 2005 |
| Thurlow Nunn Standen Limited | Wholesale & retail | 2004 |
| THW Chequers Croft Ltd | Administrative & support | 2025 |
| Timark Limited | Professional & scientific | 2005 |
| Topper Cases Limited | Manufacturing | 1950 |
| Townies Carriage Hire Limited | Transport & logistics | 2007 |
| Tracknite Limited Liability Partnership | | 2006 |
| Trackquest Limited | Real estate | 2000 |
| Translexis Limited | Professional & scientific | 1986 |
| Tripp and Co Holdings Ltd | Administrative & support | 2001 |
| U K Signs & Promotions Limited | Manufacturing | 2002 |
| Unex Group Holdings Limited | Professional & scientific | 2004 |
| Unex Holdings Limited | Real estate | 1998 |
| Upfront Publishing Limited | Information & communication | 2002 |
| Upshot Media Ltd | Administrative & support | 2005 |
| V M Associates Ltd | Professional & scientific | 2003 |
| Varsity Hotel LLP | | 2013 |