| Currans Service Station Ltd | Wholesale & retail | 2017 |
| Curry Craft Limited | Hospitality | 2026 |
| Curry Farms Limited | Agriculture & fishing | 2023 |
| Cusher Hire Limited | Administrative & support | 2012 |
| CV Sourcing LLP | | 2019 |
| Cxinmotion Limited | Information & communication | 2018 |
| Cycleology Ltd | Wholesale & retail | 2013 |
| Cyclone Air Conditioning & Ventilation Ltd | Construction | 2021 |
| Cycul Ltd | Administrative & support | 2010 |
| Cyprus Gyros Vasilis Ltd | Hospitality | 2025 |
| D & J Anderson Limited | Manufacturing | 2015 |
| D Flooring Specialist Ltd | Wholesale & retail | 2015 |
| D MAC Tyres (N.I.) Limited | Wholesale & retail | 2019 |
| D P Electrics Ltd | Construction | 2023 |
| D&G Livestock Ltd | Wholesale & retail | 2016 |
| D&J Murphy Contracts Ltd | Construction | 2025 |
| D&K Contracts Ltd | Construction | 2014 |
| D&K Hair Enhancements Ltd | Other services | 2025 |
| D.B.F. Transport Ltd | Transport & logistics | 2016 |
| D.S. Veterinary Ltd | Professional & scientific | 2019 |
| D88 Construction Ltd | Manufacturing | 2026 |
| DA Architects Ltd | Professional & scientific | 2007 |
| Daevon Property Limited | Other services | 2016 |
| Daily Bake (Ireland) Limited | Hospitality | 2015 |
| Daily Bake Holdings Limited | Financial services | 2015 |
| Daily Bake Manufacturing Ltd | Manufacturing | 2016 |
| Dala Estate Ltd | Real estate | 2023 |
| Dale Developments Armagh Limited | Real estate | 2018 |
| Dalmoy Developments Ltd | Real estate | 2026 |
| Dalton Road Promotions Ltd | Arts & recreation | 2024 |
| Daly Motor Spares Limited | Wholesale & retail | 2012 |
| DAN Winter's | Arts & recreation | 2006 |
| Dancam Limited | Administrative & support | 2019 |
| Danwill Holdings Limited | Real estate | 2026 |
| Dara Civil Engineering Ltd | Construction | 2024 |
| Dara Media Limited | Information & communication | 2014 |
| Dara Pre-School | Health & social care | 2013 |
| Darcey Site Services Ltd | Construction | 2014 |
| Darkley Produce Company Limited | Extraterritorial | 1967 |
| Dartan Hall Holdings Ltd | Agriculture & fishing | 2018 |
| Daysory Xiang Limited | Wholesale & retail | 2025 |
| Dbox Club CIC | Other services | 2022 |
| DCG Armagh Ltd | Hospitality | 2020 |
| DCX Car Sales Ltd | Wholesale & retail | 2022 |
| DDG Development Ltd | Construction | 2017 |
| DDT Haulage Limited | Transport & logistics | 2018 |
| Deanery Demesne Ltd | Construction | 2017 |
| Deansbridge Supermarket Limited | Wholesale & retail | 2003 |
| Deeside Agri Services Ltd | Wholesale & retail | 2020 |
| Deja VU Portadown Ltd | Hospitality | 2022 |
| Delizz Enterprises Ltd | Wholesale & retail | 2023 |
| Dema Business Solutions Ltd | Administrative & support | 2019 |
| Demesne Construction Ltd | Construction | 2023 |
| Demesne Engineering Ltd | Construction | 2014 |
| Dentinvent Tools Ltd | Wholesale & retail | 2024 |
| Denver Trading Limited | Extraterritorial | 2001 |
| DEP Technologies Limited | Information & communication | 2026 |
| Derriaghy Industrial Park Limited | Real estate | 2015 |
| Derry Bros Customs Clearance Ltd | Professional & scientific | 2020 |
| Derrymorgan International Transport Ltd | Transport & logistics | 2012 |
| Derrynoose Plant Hire Ltd | Construction | 2024 |
| Derrynoose Plant Limited | Administrative & support | 2021 |
| Desart Afterschools CIC | Education | 2015 |
| Desart Contracts Ltd | Construction | 2018 |
| Desart Lodge Nursery Ltd | Health & social care | 2024 |
| Despard Limited | Construction | 2012 |
| Destiny Developments (2024) Ltd | Construction | 2024 |
| Dftrees Ltd | Agriculture & fishing | 2024 |
| DG Atelier Ltd | Wholesale & retail | 2025 |
| Dialogue for Diversity | Education | 2011 |
| Diamond Taxis (Armagh) Ltd | Transport & logistics | 2011 |
| Diamond Taxis 2 Ltd | Transport & logistics | 2014 |
| Dickson Bros Poultry Ltd | Agriculture & fishing | 2024 |
| Diffin Supplies Limited | Wholesale & retail | 2019 |
| Dillay PIG Unit Limited | Agriculture & fishing | 2023 |
| Dirtworks Limited | Mining & quarrying | 2007 |
| Discount Commodity Supplies Ltd | Hospitality | 2010 |
| Dizzle Technologies Ltd | Information & communication | 2023 |
| DJ Transport Ltd | Transport & logistics | 2015 |
| Djjm Property Solutions Ltd | Real estate | 2025 |
| DJM Electrical (N.I.) Limited | Construction | 2022 |
| Djms Developments Limited | Real estate | 2003 |
| DJT Joinery Ltd | Construction | 2014 |
| DL Builders Ltd | Construction | 2017 |
| DLS Business Solutions Ltd | Professional & scientific | 2020 |
| Dlsp Limited | Real estate | 2024 |
| Dlus Recovery Limited | Health & social care | 2026 |
| DM Cleaning 8 Ltd | Administrative & support | 2022 |
| DM Sales & Marketing Ltd | Professional & scientific | 2024 |
| DMA Hughes Property Ltd | Real estate | 2023 |
| DMA Hughes Property Management Ltd | Real estate | 2026 |
| Dmac Plant Hire Ltd | Administrative & support | 2023 |
| DMG Formwork Ltd | Construction | 2021 |
| DMN Utilities Ltd | Construction | 2024 |
| DMR Direct Ltd | Real estate | 2020 |
| Dmsv Holding Ltd | Construction | 2022 |
| Dobbs Exterior Cleaning Ltd | Administrative & support | 2026 |
| DOH Equine Solutions Ltd | Wholesale & retail | 2024 |
| DOH Solutions Ltd | Hospitality | 2019 |
| Dolgan Limited | Agriculture & fishing | 1996 |