| Dingle Developments Ltd | Construction | 2021 |
| Dinin Limited | Arts & recreation | 2019 |
| Dinis Limited | Hospitality | 2021 |
| Dinky Ponies Limited | Health & social care | 2023 |
| Dinky Press Limited | Information & communication | 2016 |
| Direct Impact Ltd | Other services | 2015 |
| Direct Marketing Resource Limited | Professional & scientific | 2009 |
| Direct Partitioning Services Limited | Construction | 2021 |
| Direct Rider Services Limited | Wholesale & retail | 2017 |
| Direct Window Supplies Limited | Manufacturing | 1994 |
| Directa Associates Limited | Information & communication | 1998 |
| Disability Experts CIC | Education | 2016 |
| Discover Bikes (Swindon) Ltd | Wholesale & retail | 2025 |
| Discovery Journal Limited | Health & social care | 2024 |
| Discreetlydriven Limited | Transport & logistics | 2025 |
| Disruptive Consultancy Limited | Information & communication | 2019 |
| Distinkt Tattoos Limited | Other services | 2016 |
| Diverse Progress Solutions Ltd | Extraterritorial | 2021 |
| Diversity-Talent Community Interest Company | Other services | 2023 |
| Divide and Rule Ltd | Manufacturing | 2024 |
| Divine Care Swindon Ltd | Health & social care | 2022 |
| Divine Cars Swindon Limited | Administrative & support | 2026 |
| Divine Healthcare People Ltd | Professional & scientific | 2021 |
| Divine Presence Limited | Health & social care | 2012 |
| Divine Success Ltd | Wholesale & retail | 2020 |
| Divine Touch Beauty Salon Ltd | Other services | 2026 |
| Divjot Limited | Construction | 2025 |
| DJ Ace Holdings Limited | Real estate | 2020 |
| DJ Boswell Electrical Ltd | Construction | 2025 |
| DJ George Andrews Limited | Arts & recreation | 2018 |
| DJ Lammy Entertainment Limited | Administrative & support | 2024 |
| DJ Sanj Entertainments Ltd | Arts & recreation | 2024 |
| DJ Wiseman Roofing Ltd | Construction | 2021 |
| DJL Solutions Ltd | Professional & scientific | 2018 |
| DJS Electrical & Cctv Limited | Construction | 2019 |
| DJT Spotless Specialists Ltd | Administrative & support | 2025 |
| Dkay Properties Ltd | Real estate | 2026 |
| Dkdglobal Ltd | Wholesale & retail | 2022 |
| Dkfa Farms Ltd | Agriculture & fishing | 2025 |
| Dkhuk Ltd | Hospitality | 2024 |
| Dkmp Ltd | Transport & logistics | 2021 |
| DKT Technic Ltd | Information & communication | 2013 |
| DL Global Express Ltd | Wholesale & retail | 2018 |
| Dlara Ltd | Professional & scientific | 2025 |
| DLD 4 Ltd | Administrative & support | 2021 |
| DLG Cargo Ltd | Construction | 2021 |
| DLP Raja Ltd | Information & communication | 2016 |
| DLP Transport Ltd | Transport & logistics | 2023 |
| DLS Building Services Limited | Construction | 2014 |
| DM Logistics Solutions Limited | Transport & logistics | 2020 |
| DMA Hospitality Ltd | Hospitality | 2021 |
| DMB Electrical Services Ltd | Construction | 2015 |
| DMG Construct Ltd | Construction | 2023 |
| DMG Solutions Ltd | Transport & logistics | 2014 |
| DMH Brands Limited | Wholesale & retail | 2023 |
| DMK Electrical Ltd | Construction | 2016 |
| DML Partners Ltd | Information & communication | 2025 |
| DMM Electrical Ltd | Extraterritorial | 2026 |
| DMM Productions Ltd | Information & communication | 2014 |
| Dmnn Limited | Wholesale & retail | 2013 |
| Dmpe Limited | Construction | 2017 |
| DMS Plastering Limited | Construction | 2012 |
| DN Business Services Ltd | Administrative & support | 2025 |
| Dnfr Limited | Information & communication | 2006 |
| DNK8 Limited | Financial services | 2006 |
| DNM Industries Ltd | Transport & logistics | 2023 |
| DNN Delivery Services Ltd | Transport & logistics | 2021 |
| DNP Acres Ltd | Real estate | 2020 |
| DNQ Scaffolding Limited | Construction | 2020 |
| DNS Utility Ltd | Construction | 2021 |
| DO the Right Ting! CIC | Information & communication | 2008 |
| Doctores Muay Thai Ltd | Arts & recreation | 2025 |
| Dodeca Design & Build Ltd | Construction | 2020 |
| Doggy Day Care Swindon Ltd | Agriculture & fishing | 2020 |
| Dojo Coffee House Ltd | Hospitality | 2023 |
| Doka’S Property Ltd | Real estate | 2022 |
| Dolce Vita (Event Management) Ltd | Hospitality | 2026 |
| Domant Transport Ltd | Transport & logistics | 2026 |
| Dominion Chapel United Kingdom | Other services | 2013 |
| Domino Design and Print Limited | Manufacturing | 2019 |
| Domino Print Ltd | Manufacturing | 2021 |
| Dommett Young Limited | Health & social care | 2014 |
| Domus Churrascaria Ltd | Hospitality | 2026 |
| DON Giuliano Ltd | Energy | 2024 |
| DON Gulliver & Sons Ltd | Construction | 2006 |
| Donase Ltd | Health & social care | 2018 |
| Dondes Limited | Health & social care | 2021 |
| Donovan Construction (South West) Limited | Construction | 1993 |
| Donovan Construction Holdings Limited | Financial services | 2025 |
| Donside Developments Limited | Construction | 2015 |
| Donzai Ltd | Hospitality | 2025 |
| Doodles Tyre's Limited | Wholesale & retail | 2015 |
| Doors 4 Trade Ltd | Construction | 2018 |
| Dorcan Way Management Limited | Households | 2007 |
| Dorcas Care Ltd | Health & social care | 2023 |
| Dores Court Management Company Limited | Real estate | 2014 |
| Dorin Brothers Ltd | Transport & logistics | 2025 |
| Dormen Foods Ltd | Manufacturing | 1992 |
| Dorset Aluminium Ltd | Manufacturing | 2025 |
| DOT Enterprise Limited | Real estate | 2015 |