| Garden Room Wales Limited | Construction | 2021 |
| Garden Village AFC Limited | Arts & recreation | 2026 |
| Garden Village Cars Ltd | Wholesale & retail | 2025 |
| Gareth Davies Fitness Ltd | Arts & recreation | 2023 |
| Gareth Rees Plant Hire Limited | Construction | 1999 |
| Gareth's Delicious Delights Ltd | Manufacturing | 2019 |
| Gareth's Grassland Advisory Service Ltd | Administrative & support | 2013 |
| Garmik GAS Services Limited | Construction | 2017 |
| Garnant Pharmacy Limited | Wholesale & retail | 2008 |
| Garrington's Plaice Ltd | Hospitality | 2025 |
| Garrison Farm CIC | Real estate | 2020 |
| Garrison Farm Foods Ltd | Agriculture & fishing | 2023 |
| Garrod Beckett & Company Limited | Professional & scientific | 1992 |
| Garry Wakeham Ltd | Information & communication | 2012 |
| Garthmor Court Limited | Households | 1992 |
| Garuda Transfers Limited | Information & communication | 2020 |
| Gary Hancock Properties Ltd | Real estate | 2022 |
| GAS Care Swansea Ltd | Construction | 2025 |
| GAS Right Limited | Construction | 2025 |
| GAS Services Wales Limited | Construction | 2001 |
| Gasco Wales Ltd | Administrative & support | 2007 |
| Gastek Homesafe Limited | Construction | 2019 |
| Gateway to Wales Ltd | Administrative & support | 2016 |
| Gavin Griffiths & Daughters Properties Limited | Real estate | 2019 |
| Gavin Griffiths Contracting Ltd | Water & waste | 2013 |
| Gavin Griffiths Group Ltd | Financial services | 2024 |
| Gavin Griffiths Haulage Ltd | Transport & logistics | 2018 |
| Gavin Griffiths Property Ltd | Real estate | 2012 |
| Gavin Griffiths Recycling Ltd | Water & waste | 2005 |
| Gavin Materials Handling Limited | Manufacturing | 2009 |
| Gavin’S Home Improvements Ltd | Manufacturing | 2025 |
| Gaxtown Properties Limited | Construction | 2014 |
| Gaysha Partners LLP | | 2019 |
| GC at Founders Ltd | Other services | 2022 |
| Gcng Consultancy Limited | Information & communication | 2017 |
| Gcng Leisure Limited | Hospitality | 2016 |
| Gcng Property Limited | Real estate | 2012 |
| Gcrcb Limited | Wholesale & retail | 2009 |
| GCS Carpentry and Property Maintenance Ltd | Construction | 2024 |
| Gcsc Group Ltd | Financial services | 2023 |
| GE Swan Investment Ltd | Real estate | 2023 |
| Gealy Properties Ltd | Real estate | 2026 |
| Geared Financial Products Limited | Financial services | 2010 |
| Gebecert (UK) Limited | Information & communication | 2021 |
| GEC Events Centre Ltd | Hospitality | 2023 |
| GEE Utilities Services Limited | Construction | 2017 |
| Geek Media Limited | Information & communication | 2013 |
| Geeroscope Limited | Hospitality | 2014 |
| GEH Consultants Ltd | Administrative & support | 2011 |
| GEM & Co Properties Limited | Real estate | 2025 |
| GEM African Food Limited | Wholesale & retail | 2026 |
| GEM Autocentres Limited | Wholesale & retail | 2000 |
| Gemchronicles Limited | Wholesale & retail | 2023 |
| Gemini Mechanical Services Ltd | Construction | 2018 |
| Gemmak Engineering Limited | Manufacturing | 1974 |
| Genco Pura Olive OIL Company. Limited | Financial services | 2019 |
| Gendan Automotive Limited | Wholesale & retail | 2020 |
| Gendan Limited | Wholesale & retail | 1989 |
| Gendros Mini Travel Limited | Transport & logistics | 2019 |
| Generation B Limited | Other services | 2023 |
| Genesis Building Contractors Ltd | Construction | 2019 |
| Genesis Property Management UK Limited | Construction | 2021 |
| Genghis Solutions Limited | Professional & scientific | 2022 |
| Gentlemens Choice Image and Grooming Ltd | Other services | 2017 |
| Gents of Mumbles Ltd | Other services | 2020 |
| George Bros. of Swansea Limited | Transport & logistics | 1970 |
| George Consultancy Ltd | Professional & scientific | 2023 |
| George Property Solutions Ltd | Real estate | 2020 |
| GEP Legal Limited | Professional & scientific | 2010 |
| Geraint Jones Legal Services Limited | Professional & scientific | 2009 |
| Gerald Thomas Wealth Management Limited | Financial services | 2010 |
| Gershwins Coffee House Limited | Hospitality | 2002 |
| GET Fresh (Swansea) Limited | Wholesale & retail | 2026 |
| GET Married in France Ltd | Extraterritorial | 2005 |
| GET ME to My Wedding Limited | Administrative & support | 2017 |
| GET SET Drive School of Motoring Limited | Education | 2019 |
| GET Stuffed at Hills Limited | Hospitality | 2025 |
| Getpurebliss Cleaning Ltd | Manufacturing | 2025 |
| GEX Carpentry Ltd | Construction | 2009 |
| GEX Properties Ltd | Construction | 2023 |
| GF Gower Ltd | Wholesale & retail | 2019 |
| Gfsurveying (South West) Ltd | Professional & scientific | 2017 |
| GG Catering Solutions Ltd | Hospitality | 2024 |
| GG Plant Shop Limited | Wholesale & retail | 2025 |
| Ggbi Limited | Financial services | 2026 |
| Ggcommerce Ltd | Wholesale & retail | 2023 |
| GH Design and Build Ltd | Construction | 2021 |
| Ghutchby Investments Ltd | Real estate | 2022 |
| GI2 Ltd | Information & communication | 2019 |
| Giannini Limited | Financial services | 2022 |
| Gibbard Consulting Ltd | Professional & scientific | 2025 |
| Gibran (UK) Ltd | Education | 2006 |
| Giddyhoo Ltd | Professional & scientific | 2020 |
| Gideon Cook Associates Ltd | Administrative & support | 2011 |
| Giemme Enterprise Limited | Wholesale & retail | 2025 |
| Gifted Pleasures Ltd | Wholesale & retail | 2023 |
| Gigasyn Ltd | Information & communication | 2022 |
| Gigata Ltd | Information & communication | 2022 |
| Gigi 888 Ltd | Wholesale & retail | 2017 |
| GIGI168 Ltd | Wholesale & retail | 2017 |