| Drumgowna Poultry Ltd | Agriculture & fishing | 2015 |
| Drumgowna Properties Limited | Real estate | 2015 |
| Drumgramph Farms Ltd | Real estate | 2023 |
| Drumlin Veterinary Limited | Professional & scientific | 2013 |
| Drumlisc Properties Ltd | Real estate | 2007 |
| Drumliska Limited | Professional & scientific | 2007 |
| Drumm Engineering Limited | Professional & scientific | 2004 |
| Drummurl Poultry Ltd | Wholesale & retail | 2024 |
| Drumrainy Properties Ltd | Real estate | 2026 |
| Drumralla Stables Ltd | Agriculture & fishing | 2024 |
| Drumsara Limited | Real estate | 2022 |
| Drumsastry Eggs Ltd | Wholesale & retail | 2023 |
| Drumsloe Properties Limited | Real estate | 2024 |
| DS Agri Contracts Ltd | Agriculture & fishing | 2021 |
| DS Coaching Ltd | Education | 2024 |
| DSL Groundworks (NI) Limited | Construction | 2022 |
| Dunbarton Estates (Co Down) Limited | Real estate | 2016 |
| Duncan Bros. Limited | Administrative & support | 1988 |
| Dunlop Kitchens Ltd | Manufacturing | 2023 |
| Dunne Livestock Ltd | Agriculture & fishing | 2021 |
| Dunrunnin Group Limited | Hospitality | 2023 |
| Dunvella Ltd | Real estate | 2026 |
| DWH Food Halls Ltd | Wholesale & retail | 2001 |
| Dylan Quinn Dance Theatre | Arts & recreation | 2009 |
| E M Contracts (N.I.) Ltd | Transport & logistics | 2022 |
| E&C Developments Ltd | Construction | 2025 |
| Eadie, Mcfarland & Co. Ltd | Real estate | 2005 |
| Eamon Donnelly Developments Ltd | Construction | 2015 |
| Eamon Jones Construction Limited | Construction | 2004 |
| Eamon Martin Plastering Limited | Construction | 2005 |
| Easy Glow Ltd | Manufacturing | 2012 |
| Ecan Properties Limited | Real estate | 2022 |
| Echo Engineering Ireland Ltd | Construction | 2019 |
| Eclipse Web Services Limited | Real estate | 2015 |
| ECM Holdings Ltd | Financial services | 2021 |
| Eco Acres Limited | Manufacturing | 2016 |
| Eco Systems Direct (NI) Ltd | Extraterritorial | 2010 |
| Ecochoice Parts Limited | Wholesale & retail | 2018 |
| Ecofert Ltd | Manufacturing | 2022 |
| Eden Building Products Ltd | Construction | 2009 |
| Edenfel Limited | Real estate | 1978 |
| Eire Joinery Limited | Construction | 2013 |
| Eirsa Ltd | Information & communication | 2026 |
| Ejaz Furniture Ltd | Wholesale & retail | 2023 |
| Eknpo Ltd | Transport & logistics | 2025 |
| Eldorado Group Limited | Other services | 2018 |
| Eldorado Holdings Ltd | Financial services | 2026 |
| Eldron Construction (NI) Ltd | Real estate | 2018 |
| Eldron Logs (NI) Limited | Agriculture & fishing | 2018 |
| Electrical Holdings Ltd | Financial services | 2024 |
| Electrical Systems Ireland Ltd | Construction | 2025 |
| Electrical World Limited | Wholesale & retail | 2009 |
| Elevate Sauna & Wellness Limited | Other services | 2025 |
| Elite Electronic Systems Holdings Limited | Professional & scientific | 2014 |
| Elite Electronic Systems Ltd | Manufacturing | 1986 |
| Elite Electronics Limited | Extraterritorial | 1992 |
| Ellandco Ltd | Manufacturing | 2024 |
| Ellie's Retreat (Incorporating H-Abc Research) Limited | Hospitality | 2019 |
| Elliott Farm Ltd | Agriculture & fishing | 2011 |
| Elliott York Limited Liability Partnership | | 2005 |
| Elliott York Properties Limited | Real estate | 2016 |
| Elmira Quay Ltd | Hospitality | 2022 |
| Eloane Ltd | Wholesale & retail | 2017 |
| ELY Professional Security Services Ltd | Administrative & support | 2026 |
| EME Contracts UK Ltd | Professional & scientific | 2021 |
| EME International Ltd | Professional & scientific | 2023 |
| Emerald Land Limited | Real estate | 2023 |
| Emerald Pipe Solutions Ltd | Other services | 2007 |
| Emotional Freedom Pathways Ltd | Health & social care | 2024 |
| Empower Health Club Ltd | Arts & recreation | 2024 |
| EMT Electrical and Security Ltd | Construction | 2025 |
| Encirc Limited | Manufacturing | 1996 |
| Energy Assessment Ireland Limited | Energy | 2023 |
| Energy Management Ireland Ltd | Construction | 2014 |
| Ennis Rock Ltd | Arts & recreation | 2022 |
| Ennis View Farms Limited | Agriculture & fishing | 2018 |
| Enniskillen & District Motorcycle Club Limited | Arts & recreation | 2021 |
| Enniskillen Airport Limited | Transport & logistics | 2003 |
| Enniskillen Auctions Limited | Professional & scientific | 2014 |
| Enniskillen BID Ltd | Administrative & support | 2017 |
| Enniskillen Fobel Centre Limited | Wholesale & retail | 2008 |
| Enniskillen Memorial Remembrance Group Limited | Other services | 2022 |
| Enniskillen Nails & Spa Limited | Other services | 2025 |
| Enniskillen Photoshop Limited | Professional & scientific | 2023 |
| Enniskillen Property Developments Limited | Real estate | 1987 |
| Enniskillen Skip Hire & Recycling Limited | Extraterritorial | 2011 |
| Enniskillen Stem Academy Ltd | Education | 2024 |
| EPG Machine Tools Ltd | Agriculture & fishing | 2020 |
| Epoxy Effects Direct Ltd | Wholesale & retail | 2022 |
| Eprog Limited | Information & communication | 2005 |
| Equine MLD Ireland Limited | Professional & scientific | 2019 |
| ER Roofing & Joinery Limited | Construction | 2023 |
| Erin Vintners Ltd | Wholesale & retail | 2014 |
| Erne Adventures Limited | Arts & recreation | 2023 |
| Erne Boats Limited | Manufacturing | 2010 |
| Erne Bricklaying Co Ltd | Construction | 2015 |
| Erne Campervans Ltd | Hospitality | 2023 |
| Erne Care Limited | Health & social care | 2024 |
| Erne Educational Psychology Limited | Education | 2024 |
| Erne Environmental Limited | Professional & scientific | 2022 |