| D Mcmullan (Developments) Ltd | Construction | 2003 |
| D Robinson & SON Ltd | Construction | 2016 |
| D S Logan Limited | Wholesale & retail | 2018 |
| D&D Logistical Solutions Ltd | Wholesale & retail | 2011 |
| DAC (N.I.) Ltd | Hospitality | 2018 |
| Dailypray Ltd | Wholesale & retail | 2025 |
| Daingford NI Limited | Wholesale & retail | 2021 |
| Dandabs Limited | Information & communication | 2026 |
| Danders UK Ltd | Wholesale & retail | 2020 |
| Daniel Berevoianu Ltd | Health & social care | 2018 |
| Daniel Mcatamney Ltd | Agriculture & fishing | 2026 |
| Danlor Utilities Limited | Construction | 2003 |
| Danny Oconnell Agri Repairs Limited | Manufacturing | 2026 |
| David James Parkinson Ltd | Education | 2023 |
| Dawnmills Properties Limited | Real estate | 2012 |
| DB Construction (Ballantine) Limited | Construction | 2016 |
| DDE Haulage Ltd | Transport & logistics | 2017 |
| DE - Skill Business Solutions Ltd | Professional & scientific | 2015 |
| Deborah Mccartney Ltd | Information & communication | 2021 |
| Decofence Ltd | Administrative & support | 2017 |
| Deerfin Farm Limited | Agriculture & fishing | 2019 |
| Deerfin Property & Management Ltd | Households | 2025 |
| Deerpark AI Centre Limited | Agriculture & fishing | 2019 |
| Deerpark Wind Ltd | Energy | 2014 |
| Demanu Industrial Finishing Ltd | Manufacturing | 2026 |
| Demanu Ltd | Manufacturing | 2023 |
| Dennison Projects Ltd | Professional & scientific | 2018 |
| Denshill Garden Services Limited | Administrative & support | 2011 |
| Depower Limited | Construction | 2017 |
| Derek Burnside Limited | Construction | 2003 |
| Dermalaser Ltd | Other services | 2021 |
| Dervock & District Community Association | Real estate | 1998 |
| Dessertco Ltd | Wholesale & retail | 2019 |
| DET Banbridge Limited | Hospitality | 2015 |
| Devsol Industries Limited | Wholesale & retail | 2023 |
| DG Bakes & Cakes Ltd | Wholesale & retail | 2022 |
| DG Property Maintenance N.I. Limited | Construction | 2025 |
| DH Exchange Ltd | Wholesale & retail | 2008 |
| Dharani Group Ltd | Financial services | 2024 |
| DHB Enterprises Limited | Wholesale & retail | 2024 |
| DHU Varren Management Ltd | Real estate | 2011 |
| Dial a Dog Wash NI North Ltd | Other services | 2025 |
| Dial a Dog Wash North & East Antrim Ltd | Other services | 2024 |
| Different Lens Ltd | Other services | 2023 |
| Digsy's Diner Ltd | Hospitality | 2023 |
| Dillon Investments Limited | Administrative & support | 1989 |
| Direct Services Kosch Ltd | Wholesale & retail | 2021 |
| Dixon Property Management LLP | | 2011 |
| Dixons Contractors (Europe) Limited | Construction | 2024 |
| Dixons Contractors Ltd | Construction | 2004 |
| Dixons Investments Limited | Extraterritorial | 2017 |
| Dm-T Ecommerce Limited | Wholesale & retail | 2024 |
| DMC Antrim Ltd | Wholesale & retail | 2020 |
| DMC Auto Repairs Ltd | Wholesale & retail | 2025 |
| DMC Power Ltd | Construction | 2015 |
| DMP Foods Limited | Agriculture & fishing | 2016 |
| DNL Acquisition Ltd | Real estate | 2016 |
| Dobt Developments Ltd | Construction | 2019 |
| Docs SPV Ltd | Professional & scientific | 2026 |
| Dog Days Online Ltd | Wholesale & retail | 2020 |
| Dogleap Productions Ltd | Information & communication | 2019 |
| Doherty & Gray Limited | Manufacturing | 2000 |
| Doherty Bros Limited | Agriculture & fishing | 2013 |
| Doherty Vehicle Conversions Limited | Wholesale & retail | 2020 |
| Doherty Woodshavings Ltd | Wholesale & retail | 2012 |
| Domcleaner Ltd | Administrative & support | 2021 |
| Doneloans Limited | Financial services | 2016 |
| Donnelly 'S of Rathkenny Limited | Wholesale & retail | 2016 |
| Dontaur Engineering Limited | Manufacturing | 1977 |
| Doorlacq Limited | Construction | 2016 |
| Doranda Developments Limited | Real estate | 2013 |
| Dornan Electrical Services Limited | Manufacturing | 2025 |
| Doro Creative Limited | Professional & scientific | 2026 |
| Double Happiness (Ballymena) Limited | Hospitality | 2014 |
| Dougans Furniture Ltd | Wholesale & retail | 2017 |
| Doury Meadows Management Company Limited | Households | 2006 |
| Dowds Electrical (Holdings) Limited | Professional & scientific | 2004 |
| Dowds Energy Solutions Ltd | Construction | 2024 |
| DP Building Contracts Ltd | Construction | 2023 |
| Dppm Property Ltd | Real estate | 2019 |
| DR Drip IV Ltd | Health & social care | 2025 |
| Dragon Sun Limited | Hospitality | 2025 |
| Dreen Developments Ltd | Financial services | 2024 |
| Dreen Farm Limited | Manufacturing | 2021 |
| Dreenan Medical Ltd | Health & social care | 2016 |
| Dreennan Ltd | Wholesale & retail | 2026 |
| Drenmay Holdings Limited | Real estate | 2024 |
| Drkcp Limited | Financial services | 2019 |
| Drombane Ltd | Health & social care | 2022 |
| Drumadoon Developments Ltd | Real estate | 2024 |
| Drumbare Ltd | Manufacturing | 2023 |
| Drumbreagh Limited | Financial services | 2020 |
| Drumcarn Farms Limited | Agriculture & fishing | 2025 |
| Drumcon Pedigrees Ltd | Agriculture & fishing | 2023 |
| Drumlampth Ltd | Wholesale & retail | 2008 |
| Drumnacole Developments Ltd | Real estate | 2007 |
| Drumraw Consulting Ltd | Professional & scientific | 2025 |
| Drumraw Developments Limited | Construction | 2025 |
| Drumraw Services Ltd | Administrative & support | 2022 |
| Dse.Health Solutions Ltd | Information & communication | 2020 |