| Ross Morrison Contract Management Limited | Construction | 2014 |
| Rosslane Limited | Other services | 2004 |
| Rosso Land Ltd | Information & communication | 2014 |
| Rothbury and Associates Ltd | Professional & scientific | 2015 |
| Rothwell Rose Limited | Administrative & support | 2016 |
| Rotor Adventures International Ltd | Arts & recreation | 2025 |
| Rough and Cohort Ltd | Information & communication | 2020 |
| Roundmill Management Company Limited | Households | 2016 |
| ROW for Life Limited | Arts & recreation | 2017 |
| Royce Trading Estate Management Company Limited(The) | Real estate | 1984 |
| RP (Poundbury) LLP | | 2015 |
| Rpas Legal Limited | Professional & scientific | 2026 |
| RSL Electrical Dorset Ltd | Construction | 2026 |
| RSQ Training Limited | Education | 2015 |
| Rswong Ltd | Wholesale & retail | 2022 |
| RT Agricultural Services Ltd | Agriculture & fishing | 2025 |
| Rudkin Building Contractors Ltd | Construction | 2023 |
| Rudkin Homes Ltd | Construction | 2023 |
| Ruffle and Pearl Ltd | Wholesale & retail | 2025 |
| Rugs of Dorset Limited | Wholesale & retail | 2020 |
| Rumple Ltd | Information & communication | 2023 |
| Rupert Crew Limited | Administrative & support | 1937 |
| Rushbrook Retreat Ltd | Hospitality | 2025 |
| Rushlight Limited | Real estate | 2002 |
| Russell Philips Limited | Professional & scientific | 2013 |
| RVB Marine Limited | Professional & scientific | 2005 |
| RW Physiotherapy Ltd | Professional & scientific | 2022 |
| RYE Blinds Ltd | Construction | 2025 |
| Ryeberry Hill Limited | Administrative & support | 2011 |
| S & J Auto Salvage Limited | Water & waste | 2015 |
| S & R Downton Limited | Construction | 2002 |
| S D Broadstone Limited | Education | 2015 |
| S J E Finance Ltd | Financial services | 2020 |
| S Rowley Limited | Construction | 2002 |
| S&T Accountants Ltd | Professional & scientific | 2002 |
| S.H Landscaping Design/Build/Maintain Ltd | Administrative & support | 2025 |
| S.M.Art GAS & Plumbing Services Limited | Construction | 2007 |
| S.N. Carpentry & Joinery Limited | Manufacturing | 2018 |
| S.P.E. Roofing Limited | Construction | 2004 |
| S2A Group Ltd | Construction | 2026 |
| Sable Rock Ltd | Financial services | 2025 |
| Safehigher Safety Systems Limited | Administrative & support | 2007 |
| Saffron Holiday Homes Limited | Hospitality | 2012 |
| Sage Music Limited | Information & communication | 2019 |
| Sage Plumbing & Heating Ltd | Construction | 2025 |
| Saint Thomas Street Bicycles Ltd | Wholesale & retail | 2023 |
| SAJ Accountancy Services Limited | Professional & scientific | 2018 |
| Sakom Services (UK) Limited | Professional & scientific | 2019 |
| Sales 4.0 Ltd | Professional & scientific | 2019 |
| Salon NO.12 Limited | Other services | 2022 |
| Salt & Slate Lettings Ltd | Real estate | 2025 |
| Salt of Dorset Ltd | Wholesale & retail | 2023 |
| SAM Scaff & SON Limited | Construction | 2026 |
| SAM Systems 2012 Limited | Manufacturing | 2012 |
| Sam's Auto Electrics Limited | Wholesale & retail | 2017 |
| Sam's Business Growth Holdings Ltd | Real estate | 2025 |
| Sam's Vehicle Collection Limited | Water & waste | 2017 |
| Sami Hamed Limited | Arts & recreation | 2024 |
| Samz Healthcare Services Ltd | Health & social care | 2024 |
| Sam’S Business Growth Services Ltd | Professional & scientific | 2020 |
| Sana Health UK Limited | Administrative & support | 2015 |
| Sand and Sea Ltd | Real estate | 2016 |
| Sandford Place RTM Company Limited | Households | 2011 |
| Sands Hair Design Limited | Other services | 2010 |
| Sandy Gordon Limited | Administrative & support | 2018 |
| Sante Assure Ltd | Financial services | 2026 |
| Sante Partners Ltd | Financial services | 2019 |
| Sarah Dale Aesthetics Limited | Other services | 2012 |
| Sauna Co Ltd | Administrative & support | 2026 |
| Savage Associates Limited | Real estate | 1993 |
| Savvy Advice Limited | Administrative & support | 2007 |
| Saxonlynch Holdings Limited | Professional & scientific | 1992 |
| Scala Property Group Ltd | Real estate | 2025 |
| Scenetec Ltd | Arts & recreation | 2004 |
| Scenic Sauna Ltd | Arts & recreation | 2022 |
| Schnee Limited | Financial services | 2020 |
| School Court (Dorchester) Management Company Limited | Households | 1992 |
| Schoolofthought.Life Limited | Professional & scientific | 2020 |
| SCJ Flooring Ltd | Construction | 2019 |
| Scott Podiatry Limited | Health & social care | 2018 |
| Scottsgroup Ltd | Construction | 2019 |
| Scouts Eyes Ltd | Arts & recreation | 2023 |
| Scroggin Trail MIX Ltd | Manufacturing | 2025 |
| SDK Somerset & Dorset Limited | Wholesale & retail | 2009 |
| Sdvw Design Limited | Professional & scientific | 2019 |
| Sea Croft Studio Ltd | Professional & scientific | 2022 |
| Seabeats Limited | Hospitality | 2017 |
| Seagate House (Weymouth) Management Company Limited | Real estate | 2008 |
| Sean Williams Planning Ltd | Professional & scientific | 2019 |
| Search & Rescue Training Services (S.A.R.T.S.) Limited | Professional & scientific | 2022 |
| Searchlight Media & Copywriting Limited | Professional & scientific | 2017 |
| Seashore House (Porth) Limited | Real estate | 2005 |
| Seaside Sauna Haus Ltd | Arts & recreation | 2022 |
| Seaton Star Bar Limited | Hospitality | 2025 |
| Seatrack Limited | Information & communication | 1997 |
| Seawise Unmanned Systems Ltd | Professional & scientific | 2026 |
| SEE Water Limited | Construction | 2024 |
| Seeley Moto Limited | Wholesale & retail | 2025 |
| Self Storage Company (Dorset) Limited | Transport & logistics | 2014 |
| Selfcare Brands International Ltd | Administrative & support | 2017 |