| Dodwell Farm Livery Limited | Agriculture & fishing | 2007 |
| DOE & Co. Limited | Financial services | 2005 |
| Dofix UK Ltd | Construction | 2022 |
| Dog Besties Ltd | Wholesale & retail | 2026 |
| Doggypaddle Limited | Other services | 2007 |
| DOH Consulting Limited | Construction | 2023 |
| Doin Tech Ltd | Information & communication | 2023 |
| Dolakha Bhemeshwor Ltd | Hospitality | 2022 |
| Dollar Bar Restaurant Ltd | Professional & scientific | 2023 |
| Dollysnailemporium Ltd | Other services | 2025 |
| Dolphin Glass and Glazing Ltd | Construction | 2016 |
| Dolphin Motorhomes Limited | Wholesale & retail | 2003 |
| Dolphin Quay Management Company Limited | Households | 1990 |
| DOM Kitchens & Interiors Ltd | Construction | 2023 |
| DOM Property Development Ltd | Real estate | 2023 |
| DOM Ventas Ltd | Wholesale & retail | 2022 |
| Domain Regents Limited | Real estate | 2024 |
| Domasaze Medicare Ltd | Health & social care | 2016 |
| Dome-Shell Limited | Real estate | 2020 |
| Domi Breakfast Caffe Ltd | Hospitality | 2025 |
| Domineon Suites Limited | Real estate | 2018 |
| Dominic Transport Ltd | Transport & logistics | 2026 |
| Dominion City Southampton | Other services | 2024 |
| Domugrant Limited | Financial services | 2024 |
| DON Roper Accountant Ltd. | Professional & scientific | 2010 |
| Don'T Panic Housing Ltd | Real estate | 2025 |
| Donate IT Recycling Limited | Water & waste | 2020 |
| Doneco Ltd | Administrative & support | 2023 |
| Doner Depot Ltd | Hospitality | 2024 |
| Donington Investments Limited | Construction | 1958 |
| Donkey Wallop Productions Limited | Information & communication | 2021 |
| Dontneeddowant Ltd | Wholesale & retail | 2026 |
| Donya Limited | Professional & scientific | 2010 |
| Doodles Property & Letting Ltd | Real estate | 2024 |
| Doorbells Ltd | Real estate | 2018 |
| Doormission Ltd | Hospitality | 2019 |
| Doors & More Carpentry Ltd Ltd | Construction | 2023 |
| Doorspec Limited | Manufacturing | 2026 |
| Dopamine Corner Shop Limited | Professional & scientific | 2023 |
| DOPPELGANG3R Ltd | Arts & recreation | 2024 |
| Dorel Roofing Service Ltd | Construction | 2019 |
| Doris Jones Foundation | Extraterritorial | 2011 |
| Dorling Electrical Services Limited | Construction | 2019 |
| Dormy House (Barnes Lane) Management Limited | Real estate | 2009 |
| Dorrick Court RTE Limited | Households | 2005 |
| Dorrington Homes (UK) Limited | Construction | 2013 |
| Dorset Caravan Park 3 Limited | Hospitality | 2018 |
| Dorset Caravan Park 5 Ltd | Hospitality | 2018 |
| Dorset Heights Caravan Park Ltd | Construction | 2018 |
| Dorset Shepherd Huts Limited | Manufacturing | 2020 |
| Dorset Wheels Ltd | Manufacturing | 2012 |
| Dostdaraane Weilayat Ltd | Real estate | 2025 |
| Dotani Group of Companies Limited | Wholesale & retail | 2023 |
| Dotly Limited | Information & communication | 2020 |
| Dotnxt Ltd | Information & communication | 2022 |
| Dotted Fish Limited | Information & communication | 2015 |
| Dotty Doris Treasures Limited | Wholesale & retail | 2019 |
| Double Bubble Hamble Limited | Real estate | 2010 |
| Double D39 Transport Limited | Transport & logistics | 2021 |
| Double Glazing Southampton Ltd | Construction | 2023 |
| Dough Bros Pizza Co Ltd | Hospitality | 2023 |
| Douglas Dunlop Limited | Health & social care | 2005 |
| Douglas Logistics Ltd | Transport & logistics | 2017 |
| Dourdough Ltd | Professional & scientific | 2021 |
| Dove Property Portfolio Ltd | Real estate | 2020 |
| Dovecote Dental Care Limited | Health & social care | 2021 |
| Dovecote Systems Ltd | Energy | 2026 |
| DOW Schofield Watts Principal Partners LLP | | 2024 |
| Downland Design Limited | Professional & scientific | 1994 |
| Doxa Encounters Ministries Ltd | Education | 2025 |
| Doyle & Palmer Wealth Management Limited | Financial services | 2010 |
| DP (BD) Ltd | Hospitality | 2023 |
| DP Construction and Refurbishments Ltd | Construction | 2019 |
| DP Consulting Hampshire Limited | Professional & scientific | 2024 |
| DP153 Management Limited | Households | 2022 |
| DP188 Management Limited | Households | 2023 |
| DP197 Management Limited | Households | 2022 |
| DP5 Investments Ltd | Financial services | 2024 |
| Dpad Ltd | Other services | 2024 |
| Dperfetto Ltd | Wholesale & retail | 2021 |
| DPM (Hampshire) LLP | | 2022 |
| DPM Builder Ltd | Construction | 2016 |
| DPS Business Services Ltd | Professional & scientific | 2020 |
| DPS GP Solutions Ltd | Administrative & support | 2019 |
| DPS Quality Carpentry Ltd | Construction | 2022 |
| DPV (Platinum) Ltd | Real estate | 2017 |
| DQ Dent Removal Limited | Wholesale & retail | 2018 |
| DR & JR Investments Limited | Financial services | 2017 |
| DR & JR Properties 2 Ltd | Real estate | 2025 |
| DR & JR Properties Limited | Real estate | 2017 |
| DR Andrew Cowan Ltd | Health & social care | 2012 |
| DR Asgarov Limited | Administrative & support | 2014 |
| DR Kora-Advanced Medical Aesthetics and Skin Care Ltd | Health & social care | 2023 |
| DR Lucy Ilie Ltd | Health & social care | 2016 |
| DR Newco Limited | Manufacturing | 2023 |
| DR Pest & Clean Ltd | Administrative & support | 2026 |
| DR RAI Aesthetics Ltd | Other services | 2024 |
| DR Satnam Louis Ltd | Health & social care | 2006 |
| DR. Stuart Batistich Limited | Health & social care | 2011 |
| Dr.Ukhan Limited | Health & social care | 2025 |