| Glen Garth Garden Centre Limited | Wholesale & retail | 2023 |
| Glenerne Limited | Construction | 2019 |
| Glenwinny Limited | Manufacturing | 2020 |
| Glenzar Limited | Hospitality | 2017 |
| GLO UP Limited | Other services | 2025 |
| Global Bins (Multi) Ltd | Water & waste | 2017 |
| Global OIL Recovery Ltd | Manufacturing | 2011 |
| GLÖ Sauna Limited | Health & social care | 2025 |
| GMD Highway Services Limited | Wholesale & retail | 1994 |
| Gmmr Property Ltd | Real estate | 2026 |
| Goitia-Macdonald Properties Ltd | Real estate | 2024 |
| Goldland Merchants Limited | Wholesale & retail | 2001 |
| Goldmar Contracts Ltd | Construction | 2019 |
| Goldsboro Limited | Real estate | 2014 |
| Golf Tech Holding Ltd | Professional & scientific | 2022 |
| Gollanfastfood T/A Apache Pizza Ltd | Hospitality | 2025 |
| Good Mood Food Ltd | Wholesale & retail | 2017 |
| Gorgesh Limited | Real estate | 2003 |
| Gormley Contracts Limited | Construction | 2017 |
| Gormley Kitchens Ltd | Manufacturing | 2004 |
| Gormley Precision Joinery Ltd | Construction | 2013 |
| Gorteen Building Solutions Ltd | Construction | 2015 |
| Gortmaconnell Farms Limited | Agriculture & fishing | 2019 |
| Goulding Engineering Ltd | Manufacturing | 2023 |
| Gourmet Bros Ltd | Hospitality | 2021 |
| Gourmet Bros. Retail Ltd | Wholesale & retail | 2021 |
| GP Direct Ltd | Health & social care | 2026 |
| GPM Entertainment Limited | Arts & recreation | 2023 |
| GPO Contracts Ltd | Construction | 2021 |
| Gradan Holdings Limited | Construction | 2021 |
| Grady Joinery UK Limited | Construction | 2007 |
| Graffy Entertainment Ltd | Arts & recreation | 2025 |
| Graham Irvine Architect Limited | Professional & scientific | 2024 |
| Graphic Craft Limited | Manufacturing | 2023 |
| Grays Clip Limited | Manufacturing | 2015 |
| GRB Estates Limited | Real estate | 2022 |
| GRB Limited | Real estate | 2025 |
| GRB Property Limited | Real estate | 2021 |
| GRB Solicitors Limited | Professional & scientific | 2015 |
| Green Hedges Limited | Arts & recreation | 2021 |
| Green Sword Environmental Ltd | Professional & scientific | 2013 |
| Greene Locum Ltd | Other services | 2022 |
| Greenergy Consultancy Services Ltd. | Professional & scientific | 2016 |
| Greenshoots (NI) Community Interest Company | Administrative & support | 2013 |
| Greentown Environmental Ltd | Transport & logistics | 2011 |
| Greentown Traffic Management Limited | Transport & logistics | 2015 |
| Gretm Ltd | Real estate | 2024 |
| Greystone Cars Ltd | Wholesale & retail | 2021 |
| GRG Foods Ltd | Manufacturing | 2016 |
| GRG Hospitality Ltd | Hospitality | 2023 |
| GRJ Properties Limited | Real estate | 2015 |
| GRM House Ltd | Real estate | 2005 |
| Group Technologies Ltd | Information & communication | 2022 |
| Grove Lough Energy Limited | Energy | 2013 |
| Growflow Capital Limited | Financial services | 2025 |
| GS Ewing & Sons Ltd | Wholesale & retail | 2026 |
| GS International Recruitment Ltd | Administrative & support | 2019 |
| GSC Haulage Ltd | Transport & logistics | 2016 |
| GTM Solutions Ltd | Wholesale & retail | 2020 |
| Gulli Technology Limited | Information & communication | 2014 |
| Gunntrack Services Ltd | Construction | 2025 |
| H & W Wind Energy Ltd | Energy | 2026 |
| H. E. Tenacity Limited | Real estate | 2021 |
| H32 Wholesale Limited | Wholesale & retail | 2019 |
| Hall Farm Eggs Limited | Agriculture & fishing | 2016 |
| Halo Property Investments Ltd | Real estate | 2016 |
| Hambly & Hambly Gallery Limited | Arts & recreation | 2017 |
| Hamilton Trailers Ltd | Manufacturing | 2023 |
| Hand Transport Limited | Transport & logistics | 2016 |
| Handforth One Ltd | Wholesale & retail | 2025 |
| Happythreads (UK) Ltd | Wholesale & retail | 2019 |
| Hargan Marine Services Ltd | Transport & logistics | 2021 |
| Harolds Cross Estates Limited | Real estate | 2017 |
| Harron Asset Management Ltd | Real estate | 2021 |
| Hassard Mcclements (2024) Limited | Professional & scientific | 2024 |
| Haven Homes Ireland Limited | Construction | 2025 |
| Hawk Oils Ltd | Manufacturing | 2020 |
| Haymeadow Limited | Agriculture & fishing | 2009 |
| Headlines Hair Salon Ltd | Other services | 2026 |
| Health Fit LAB Ltd | Arts & recreation | 2023 |
| Healthelocum Ltd | Health & social care | 2019 |
| Heli Challenge Limited | Other services | 2011 |
| Heli Torque Ltd | Manufacturing | 2025 |
| Helicopter Times Ltd | Transport & logistics | 2018 |
| Hellfire Consulting Ltd | Administrative & support | 2025 |
| Henry Pierce & Sons, Limited | Construction | 1949 |
| Hertz Cars Ltd | Wholesale & retail | 2024 |
| Hetherington Properties Limited | Real estate | 2006 |
| Hics Properties Ltd | Construction | 2006 |
| Hidden Beauty at Coolaness Ltd | Other services | 2025 |
| Hidden Beauty Retreat Ltd | Other services | 2025 |
| Highbridge Contracts Ltd | Construction | 2011 |
| Highgate Poultry Ltd | Agriculture & fishing | 2014 |
| Hiline Haulage Ltd | Transport & logistics | 2018 |
| Hillcrest Free Range Eggs Ltd | Wholesale & retail | 2018 |
| Hire and Admire Blooms Ltd | Administrative & support | 2023 |
| Holden Contracts Ltd | Construction | 2025 |
| Hollyview Limited | Wholesale & retail | 2008 |
| Holwin Limited | Professional & scientific | 2024 |
| Home & Stone Limited | Wholesale & retail | 2017 |