| Daly Park & Company Ltd | Professional & scientific | 2002 |
| Damolly Lane Management Limited | Households | 2026 |
| DAN O'Hare Holdings Limited | Financial services | 2025 |
| DAN Tranz Ltd | Transport & logistics | 2021 |
| Dance Associate Ltd | Education | 2012 |
| Dance Awards Ireland (Roi/Ie) CIC | Arts & recreation | 2024 |
| Danny Byrne Band Ltd | Arts & recreation | 2026 |
| Danny Mcshane Ltd | Agriculture & fishing | 2020 |
| Danoam Limited | Real estate | 2017 |
| Danro Joinery Ltd | Construction | 2022 |
| Danson Partners L.P. | | 2015 |
| Daran Hollywood Signs Ltd | Manufacturing | 2021 |
| Darcof Ltd | Professional & scientific | 2025 |
| Dargan Crescent (2025) Limited | Financial services | 2025 |
| Darlene Jayda Madden Ltd | Extraterritorial | 2025 |
| Darren O'Hagan Contracts Ltd | Construction | 2018 |
| Dartmax Communications L.P. | | 2015 |
| Dash Grooming Room Limited | Other services | 2024 |
| Data Protection Services AI Ltd | Information & communication | 2025 |
| DATA4U Ltd | Wholesale & retail | 2025 |
| Datacord L.P. | | 2017 |
| David Buckley Plant Limited | Administrative & support | 2005 |
| David Byrne Transport Ltd | Transport & logistics | 2023 |
| David Cowpe Ltd | Wholesale & retail | 2024 |
| David John Nesbitt Limited | Professional & scientific | 2026 |
| David Maxwell Chartered Architect Ltd | Professional & scientific | 2010 |
| David Mckee Contracts Limited | Construction | 2010 |
| David Transit L.P. | | 2017 |
| Davina's ARK (Aftercare Addiction Centre) | Health & social care | 2013 |
| Davis Furniture Limited | Wholesale & retail | 2019 |
| Dawson Transport Ltd | Transport & logistics | 2003 |
| Db-Designz Ltd | Manufacturing | 2022 |
| DBD Electrical (Ireland) Limited | Construction | 2017 |
| DBH Properties NI Limited | Real estate | 2014 |
| DBL Motor Group Ltd | Wholesale & retail | 2026 |
| DBM FOX Holdings Limited | Real estate | 2017 |
| DC Cattle Ltd | Agriculture & fishing | 2003 |
| DCE Formwork Ltd | Construction | 2025 |
| Dcpm Holdings Ltd | Financial services | 2025 |
| Dcsm Hire Ltd | Construction | 2025 |
| Dcsm Scaffolding Ltd | Construction | 2024 |
| DCT Digital Construction Technologies Limited | Professional & scientific | 2024 |
| DD Pubs Limited | Financial services | 2025 |
| DDC Fire Sprinkler Design Limited | Professional & scientific | 2024 |
| Ddctd Apparel Ltd | Wholesale & retail | 2021 |
| DDH Contracts Ltd | Construction | 2025 |
| Ddieci UK Ltd | Extraterritorial | 2010 |
| DDT Group Limited | Hospitality | 2020 |
| DE (Belmont Road) Ltd | Health & social care | 2015 |
| DE Contracts Ltd | Construction | 2018 |
| DE Empire Limited | Wholesale & retail | 2025 |
| DE Sales N.I. Ltd | Wholesale & retail | 2018 |
| Deacci Ltd | Manufacturing | 2013 |
| Deals & Dough Ltd | Wholesale & retail | 2026 |
| Deanery Demesne Management Limited | Households | 2019 |
| Deanrp Ltd | Construction | 2025 |
| DEC Motors Ltd | Wholesale & retail | 2024 |
| Decam Plumbing & Heating Ltd | Construction | 2026 |
| Declan Mcchesney Shoe Agencies Ltd | Wholesale & retail | 2015 |
| Declan Mullen Contracts Ltd | Construction | 2017 |
| Dedicated by Doyle Ltd | Arts & recreation | 2021 |
| Dedicated Fitness Gym Limited | Arts & recreation | 2017 |
| DEE Agnew Design Limited | Professional & scientific | 2024 |
| Deerfort Limited | Manufacturing | 2023 |
| Defi Tax Consultants Ltd | Professional & scientific | 2022 |
| Degens Film Ltd | Information & communication | 2025 |
| Deja VU Beauty Ltd | Other services | 2013 |
| DEL Autos Ltd | Wholesale & retail | 2023 |
| DEL Norte Tapas & Trading Ltd | Hospitality | 2025 |
| DEL Promotions Ltd | Arts & recreation | 2025 |
| Delahunt Design Ltd | Professional & scientific | 2011 |
| Delahunt Retail (UK) Ltd | Wholesale & retail | 2020 |
| Delgado HR Limited | Administrative & support | 2025 |
| Deliverance AI Ltd | Information & communication | 2026 |
| Delivis Ltd | Transport & logistics | 2019 |
| Delta Distributors AE Limited | Wholesale & retail | 2020 |
| Delta Investment Holdings Limited | Financial services | 2018 |
| Delta Mech Ltd | Construction | 2020 |
| Delta Tech Mechanical Ltd | Construction | 2023 |
| Deltawest L.P. | | 2015 |
| Deltec Group Ltd | Professional & scientific | 2021 |
| DEM Contracts Ltd | Construction | 2018 |
| Dem-Con (N.I.) Limited | Construction | 2018 |
| Demac Construction Ltd | Construction | 2016 |
| Demenex Limited | Real estate | 2013 |
| Demoan Farms Ltd | Transport & logistics | 2025 |
| Demp Holding Limited | Financial services | 2022 |
| Demp Leasing Limited | Administrative & support | 2022 |
| DEN Contracts Ltd | Construction | 2003 |
| Dentamed Newry Limited | Health & social care | 2016 |
| Dentex Commodities L.P. | | 2015 |
| Derby Transport Ltd | Transport & logistics | 2014 |
| Derek Mcdowell & Sons Ltd | Construction | 2007 |
| Dermot Joseph Rice Limited | Extraterritorial | 2022 |
| Dermview (U.K.) Limited | Information & communication | 2022 |
| Dermy Boyle Electrical Ltd | Construction | 2020 |
| Derrybeg Shop Ltd | Wholesale & retail | 2018 |
| Derrylecka Bedding & Furniture Ltd | Wholesale & retail | 2020 |
| Derryleckagh Contracts Ltd | Construction | 2012 |
| Derrymore Energy Ltd | Energy | 2024 |