| Gary Watson Motor Company Limited | Wholesale & retail | 2008 |
| GB Motors & Repairs Ltd | Manufacturing | 2026 |
| Gbkennedyisw Ltd | Health & social care | 2026 |
| GCH Flooring & Designs Ltd | Construction | 2018 |
| GD Graphics Ltd | Information & communication | 2009 |
| GDC Consult Limited | Financial services | 2014 |
| GDH Leatherwork Ltd | Information & communication | 2019 |
| GDM Construction Limited | Construction | 2000 |
| GDT Envirocare Ltd | Administrative & support | 2017 |
| GE Construction Surveying Ltd | Professional & scientific | 2010 |
| Gear Technology Limited | Information & communication | 2020 |
| GEE WIZ Property Limited | Real estate | 2017 |
| GEM Commercial Parts Ltd | Wholesale & retail | 2025 |
| Genero Creative Ltd | Other services | 2015 |
| Genero Group Holdings Ltd | Financial services | 2021 |
| Genero Productions Limited | Other services | 2006 |
| Genius PAY Solutions Limited | Administrative & support | 2023 |
| George's NO. 1 Limited | Other services | 2014 |
| Gibbonsdown Childrens Centre Limited | Education | 2001 |
| Giles & Doyle Ltd | Financial services | 2022 |
| Gillen Associates Ltd | Wholesale & retail | 2024 |
| Giorgia Wakeham Ltd | Wholesale & retail | 2026 |
| Girl & BOY Design Limited | Information & communication | 2015 |
| GJ Care and Training Ltd | Health & social care | 2008 |
| GJD Aerotech Limited | Manufacturing | 2007 |
| GKA Dojo CIC | Education | 2024 |
| Gladstone Garden Court Management Company Limited | Households | 1989 |
| Glamorgan Bars Ltd | Hospitality | 2025 |
| Glamorgan Foods Ltd | Hospitality | 2024 |
| Glamorgan GUN Room Ltd | Wholesale & retail | 2020 |
| Glamorgan H&S Ltd | Other services | 2026 |
| Glan Hafren Property Company Limited | Households | 1975 |
| Glan Y DWR (Barry) RTM Company Ltd | Households | 2021 |
| Glan Y MOR RTM Limited | Administrative & support | 2010 |
| Glass Shot LLP | | 2006 |
| Glenmor Estates Limited | Real estate | 2000 |
| Glenmore Systems Ltd | Real estate | 2014 |
| Glistening Limited | Administrative & support | 2023 |
| Globusnet Ltd | Wholesale & retail | 2017 |
| GLR Bespoke Services Ltd | Construction | 2018 |
| GMB Paving Ltd | Construction | 2019 |
| Go Business Loans Limited | Financial services | 2015 |
| Go Commercial Finance Ltd | Financial services | 2013 |
| Golau Business Development Limited | Administrative & support | 2024 |
| Golden Panda Ltd | Hospitality | 2025 |
| Goleuo Ltd | Professional & scientific | 2025 |
| Good Agents Holidays Ltd | Administrative & support | 2025 |
| Goodlife Eco Centre Ltd | Construction | 2014 |
| Goodman Equestrian Supplies Ltd | Wholesale & retail | 2017 |
| Goranz Ltd | Other services | 2026 |
| Gordon Sealey & Associates Limited | Professional & scientific | 2008 |
| Gorse and Gossamer Ltd | Manufacturing | 2025 |
| Governor Investments Limited | Real estate | 2012 |
| Gower Healthcare Dental Ltd | Health & social care | 2020 |
| Gowlog Farm Ltd | Agriculture & fishing | 2025 |
| Grab IT Intergrated Services Ltd | Construction | 2017 |
| Graceful Home Care Limited | Health & social care | 2023 |
| Gradon Close Flat Management Limited | Extraterritorial | 2009 |
| Graduate Collection Limited | Wholesale & retail | 2026 |
| Graiglwyd Limited | Administrative & support | 2008 |
| Gram (Properties) Limited | Real estate | 1998 |
| Granada Properties Ltd | Real estate | 2025 |
| Grand Events Catering Limited | Hospitality | 2025 |
| Grange Court Residents Association (Barry) Ltd | Households | 2006 |
| Grant & Co Asset Management Limited | Real estate | 2012 |
| Grant & Co Consultants Limited | Real estate | 2009 |
| Grassroots Sports Lottery C.I.C. | Arts & recreation | 2020 |
| Gravelle's Mobility & Lifestyle Limited | Wholesale & retail | 2006 |
| Gravelles Facilities Management (GFM) Ltd | Real estate | 2022 |
| Graven Guild Ltd | Arts & recreation | 2017 |
| Greek 2025 Ltd | Hospitality | 2025 |
| Greek Islands Limited | Hospitality | 2023 |
| Green Circle Concrete Limited | Administrative & support | 2008 |
| Green Energy Robotics Ltd | Professional & scientific | 2019 |
| Green Housekeeping Ltd | Other services | 2018 |
| Green Money Ltd | Financial services | 2018 |
| Greenacres Landscaping Ltd | Administrative & support | 2025 |
| Greenbrick Group Ltd | Construction | 2019 |
| Greenpoint IT Ltd | Wholesale & retail | 2007 |
| Griffin Engineering Ltd | Professional & scientific | 2023 |
| Grill Next Door Limited | Hospitality | 2023 |
| Grounds Maintenance by Four Seasons Limited | Administrative & support | 2025 |
| Grove Autocare Limited | Administrative & support | 2014 |
| Grove Site Services Ltd | Administrative & support | 2020 |
| GS 17 Limited | Hospitality | 2023 |
| GSM PVT Ltd | Hospitality | 2024 |
| GT Maintenance & Flooring Limited | Administrative & support | 2024 |
| Guaranteed Touch Ltd | Construction | 2024 |
| Gunshon Group Ltd | Wholesale & retail | 2022 |
| Gursatsingh UK Limited | Hospitality | 2025 |
| Gwesty-Glynarthen Limited | Hospitality | 2010 |
| GWG Wellbeing Ltd | Information & communication | 2014 |
| Gwynt HV Ltd | Energy | 2025 |
| Gym Central Limited | Wholesale & retail | 2014 |
| Gym Lease Hire Solutions Ltd | Administrative & support | 2025 |
| H W R 168 Limited | Hospitality | 2016 |
| H&M Property Solutions Ltd | Construction | 2025 |
| H&T Installations Limited | Construction | 2017 |
| H.Marshall Plumbing and Heating Services Ltd | Construction | 2024 |
| H.Thomas Welding Ltd | Construction | 2023 |