| Glamorgan Cheeses Ltd | Wholesale & retail | 2017 |
| Glamorgan Fixing Company Limited | Construction | 2016 |
| Glamorgan Home Care Limited | Health & social care | 2009 |
| Glamorgan Interiors Limited | Construction | 2015 |
| Glamorgan Premium Renovation Ltd | Construction | 2025 |
| Glamorgan Prestige Ltd | Other services | 2017 |
| Glamorgan Properties Limited | Real estate | 1997 |
| Glamorgan Ventures Limited | Wholesale & retail | 2011 |
| Glamorganshire Grass Roots Limited | Administrative & support | 2015 |
| Glamorous Journey Limited | Other services | 2025 |
| Glamorous World Limited | Wholesale & retail | 2025 |
| Glamour Cosmetic Clinic Ltd | Administrative & support | 2014 |
| GLAMPGLAMP15 Limited | Hospitality | 2019 |
| Glamrise International Limited | Wholesale & retail | 2025 |
| Glamurb Group Ltd | Wholesale & retail | 2024 |
| Glan Hafren Residents Management Company Limited | Real estate | 2010 |
| Glan Rhymni Ltd | Wholesale & retail | 2019 |
| Glan-Y-Llyn Management Limited | Real estate | 2005 |
| Glandem Consulting Limited | Professional & scientific | 2023 |
| Glandx Ltd | Manufacturing | 2025 |
| Glanford Brothers Limited | Manufacturing | 2024 |
| Glantz Software Consulting Limited | Administrative & support | 2015 |
| Glas Cymru (Securities) Cyfyngedig | Financial services | 2000 |
| Glas Cymru Anghyfyngedig | Water & waste | 2000 |
| Glas Cymru Holdings Cyfyngedig | Water & waste | 2015 |
| Glas Quality Holdings Co Ltd | Financial services | 2023 |
| Glas Tiger Ltd | Construction | 2020 |
| Glasgow Masterclass Ltd | Administrative & support | 2018 |
| Glasgowdessertcompany Ltd | Hospitality | 2019 |
| Glass Corner Ltd | Wholesale & retail | 2026 |
| Glass Cutting Ltd | Professional & scientific | 2020 |
| Glass Full Flowers Limited | Wholesale & retail | 2019 |
| Glass Tailors Ltd | Wholesale & retail | 2017 |
| Glasshouse Developments LLP | | 2024 |
| Glasshouse Interiors Limited | Manufacturing | 2014 |
| Glasshouse Pictures Limited | | 1987 |
| Glasstastique Limited | Health & social care | 2005 |
| Glassworks Tech Limited | Information & communication | 2025 |
| Glata Capital Limited | Administrative & support | 2021 |
| Glaves Commercial Properties Ltd | Real estate | 2024 |
| Glavineo Ltd | Wholesale & retail | 2025 |
| Glazara Ltd | Education | 2025 |
| Glaze Master Limited | Construction | 2018 |
| Glazing Vans Limited | Extraterritorial | 2008 |
| GLB Transport Ltd | Transport & logistics | 2007 |
| GLC Mgmt Services Ltd | Information & communication | 2022 |
| Gleam & Sheen Auto Care Ltd | Administrative & support | 2025 |
| Gleam Holdings Ltd | Wholesale & retail | 2026 |
| Gleaming Marvellous Ltd | Administrative & support | 2019 |
| Gleamore Ltd | Wholesale & retail | 2025 |
| Gleamwave Ltd | Wholesale & retail | 2024 |
| Gleision Limited | Information & communication | 2008 |
| Glemin Associates Limited | Health & social care | 2023 |
| Glen Harry Holdings Ltd. | Professional & scientific | 1997 |
| Glen Tromie Invest Limited | Extraterritorial | 2021 |
| Glena Ltd | Information & communication | 2020 |
| Glenal Strath Ltd | Wholesale & retail | 2023 |
| Glenaub House Management Company Limited | Real estate | 2005 |
| Glencar Services Limited | Professional & scientific | 2007 |
| Glencove Web Industries (UK) Limited | Administrative & support | 2015 |
| Gleneagles Court (Cardiff) Management Company Limited | Households | 1999 |
| Gleneco Renewable Heating Ltd | Construction | 2019 |
| Glenino Car Ltd | Wholesale & retail | 2026 |
| Glenisle Properties Limited | Real estate | 1958 |
| Glenmalure Consulting Ltd | Information & communication | 2019 |
| Glenn Wills Limited | Arts & recreation | 2009 |
| Glenroy Property Management Limited | Hospitality | 2011 |
| Glenside Court Co. Limited | Households | 1996 |
| Glenwillow Ltd | Health & social care | 2025 |
| Glestu | Professional & scientific | 2023 |
| Glevkor Ltd | Information & communication | 2026 |
| GLG Finance Ltd | Professional & scientific | 2019 |
| Glhl Properties Limited | Real estate | 2025 |
| Glide Equine Limited | Agriculture & fishing | 2025 |
| Glintfable Enterprises Limited | Information & communication | 2024 |
| Glittermilkshake Ltd | Transport & logistics | 2019 |
| Glitzi Ltd | Manufacturing | 2016 |
| GLJ Properties Ltd | Real estate | 2020 |
| GLL Company Limited | Wholesale & retail | 2015 |
| GLM Financial Ltd | Professional & scientific | 2023 |
| GLM Technology Ltd | Wholesale & retail | 2025 |
| GLN Renewables Ltd | Construction | 2021 |
| Glo-Belle Ltd | Administrative & support | 2013 |
| Glo-Rum Enterprise Limited | Manufacturing | 2017 |
| Global 777 Limited | Construction | 2013 |
| Global A&M Ltd | Wholesale & retail | 2024 |
| Global Academic Consortium Ltd | Financial services | 2016 |
| Global Advisink Consultancy Ltd | Information & communication | 2015 |
| Global AG Ltd | Administrative & support | 2016 |
| Global Aimsuk Limited | Professional & scientific | 2014 |
| Global Alliance Commodities Ltd | Financial services | 2025 |
| Global Apex Vibe Fashion Limited | Wholesale & retail | 2026 |
| Global Associate & Business Consultant UK Ltd | Information & communication | 2013 |
| Global Automotive Ltd | Wholesale & retail | 2014 |
| Global Beauty Services Limited | Arts & recreation | 2017 |
| Global Biomolecular Technologies Ltd | Manufacturing | 2020 |
| Global Bridal Brands Limited | Manufacturing | 2013 |
| Global Business Holdings Ltd | Information & communication | 2018 |
| Global Carbon Neutral Research Association Ltd | Professional & scientific | 2022 |
| Global Central Financing Limited | Professional & scientific | 2015 |