| Gowerton Golf Range Ltd | Arts & recreation | 2025 |
| Gowerton Rugby Football Club Limited | Arts & recreation | 2020 |
| GPC Systems Ltd | Information & communication | 2010 |
| GR Digital Ltd | Information & communication | 2016 |
| GRA Commercial Services Ltd | Professional & scientific | 2020 |
| Grace Garden Limited | Hospitality | 2026 |
| Grace-X AI Ltd | Information & communication | 2026 |
| Grace.Hs Limited | Other services | 2024 |
| Gracefavour Limited | Real estate | 1993 |
| Graceful Numbers Europe Ltd | Professional & scientific | 2017 |
| Gracevine Ltd | Wholesale & retail | 2024 |
| Graffeg Lliw Limited | Professional & scientific | 2021 |
| Graham & Co Properties Ltd | Real estate | 2019 |
| Graham a Jones (Lofts & Extensions) Ltd | Construction | 2021 |
| Graham Evans & Partners LLP | | 2010 |
| Graham Evans Solicitors Limited | Extraterritorial | 2012 |
| Graham's Heating & Plumbing Ltd | Construction | 2010 |
| Graig Management and Maintenance Ltd | Professional & scientific | 2024 |
| Grail Gallery Ltd | Wholesale & retail | 2024 |
| Granada Court RTM Limited | Households | 2010 |
| Grand Residence Real Estate Ltd | Real estate | 2023 |
| Grand Slam Theatre Company Ltd | Arts & recreation | 2008 |
| Grandlees Limited | Real estate | 2007 |
| Grandvale Properties Limited | Real estate | 2007 |
| Grange Maintenance Co. Limited | Households | 1991 |
| Grange Sports (UK) Limited | Wholesale & retail | 2019 |
| Granite by Alex Ltd | Manufacturing | 2023 |
| Granite Specialist Limited | Wholesale & retail | 2011 |
| Granite Worktops Limited | Manufacturing | 2001 |
| Graphic Realm Ltd | Manufacturing | 2004 |
| Gravell Capital Ltd | Financial services | 2025 |
| Gravitable Ltd | Professional & scientific | 2022 |
| Gray Legacy Properties Ltd | Construction | 2024 |
| Grayson Property Group Ltd | Real estate | 2023 |
| GRB Solutions Ltd | Professional & scientific | 2022 |
| GRE Electrical Services Limited | Construction | 2024 |
| Great Green Kitchen Ltd | Hospitality | 2020 |
| Great Highway Properties LLP | | 2016 |
| Great Neighborhoods UK Limited | Real estate | 2023 |
| Great Pitton Farms Ltd | Agriculture & fishing | 2022 |
| Great Wall Swansea Ltd | Hospitality | 2022 |
| Greek Flavours Mumbles Limited | Hospitality | 2023 |
| Greek Flavours Swansea Limited | Hospitality | 2021 |
| Greek Street Food Swansea Limited | Hospitality | 2022 |
| Greek Street Swansea Ltd | Hospitality | 2025 |
| Greekland Kitchen Ltd | Hospitality | 2026 |
| Green Acorn Ventures Ltd | Construction | 2020 |
| Green ANT Games Limited | Information & communication | 2010 |
| Green Bank (Pennard) Management Company Limited | Households | 1989 |
| Green Castle Financial Planning Ltd | Financial services | 2021 |
| Green Core Utility Solutions Ltd | Construction | 2024 |
| Green Dragon Holdings (Swansea) Limited | Financial services | 2024 |
| Green Dragon Properties (Swansea) Limited | Construction | 2024 |
| Green Dragon Renewables Limited | Construction | 2024 |
| Green Dream Concepts Ltd | Construction | 2023 |
| Green Energy Cornwall Ltd | Construction | 2022 |
| Green Energy Feckenham Ltd | Construction | 2022 |
| Green Energy MAB Ltd | Construction | 2022 |
| Green Energy Solar Ltd | Administrative & support | 2021 |
| Green HAT Consulting Limited | Professional & scientific | 2013 |
| Green Path Consulting Ltd | Information & communication | 2010 |
| Green Scene Swansea CIC | Education | 2022 |
| Green SET Solutions Limited | Professional & scientific | 2025 |
| Green Steel Works Ltd | Water & waste | 2017 |
| Green Tech Digital & Recruitment Ltd | Information & communication | 2025 |
| Green Valley Country Club Constanza Limited | Construction | 2021 |
| Green Valley Country Club LAS Terrenas Limited | Construction | 2021 |
| Green Valley Woodcraft CIC | Education | 2025 |
| Green Wall Properties Limited | Real estate | 2018 |
| Green-Link Electrical Services Ltd | Construction | 2022 |
| Greenacre Escapes Ltd | Hospitality | 2023 |
| Greencabinwales Ltd | Professional & scientific | 2022 |
| Greencock Enterprises Limited | Real estate | 2021 |
| Greenedge Renewables Ltd | Construction | 2025 |
| Greenfield Pound Limited | Other services | 2014 |
| Greengrass Solutions Ltd | Real estate | 2021 |
| Greenheart Carpentry Limited | Construction | 2012 |
| Greeno's Cafe Limited | Hospitality | 2025 |
| Greenoaks Plastering & Building Ltd | Construction | 2026 |
| Greenow Limited | Administrative & support | 2010 |
| Greens Complete Contract Maintenance Limited | Construction | 2022 |
| Greens Construction Ltd | Construction | 2015 |
| Greens Luxury Kitchens Ltd | Construction | 2024 |
| Greens Precise Plumbing & Heating Ltd | Construction | 2020 |
| Greens Property and Investments Limited | Real estate | 2022 |
| Greensave Systems Ltd | Construction | 2025 |
| Greenshire International Ltd | Real estate | 2020 |
| Greenslade Management Limited | Real estate | 1973 |
| Greenwarm CYF | Construction | 2026 |
| Greenway Homes Developments Ltd | Construction | 2016 |
| Greenwood Louvre Limited | Manufacturing | 2010 |
| Greenwood Mechanical Labour Limited | Manufacturing | 2013 |
| Greet N EAT Ltd | Hospitality | 2025 |
| Greetings (Swansea) Limited | Wholesale & retail | 2002 |
| Greg Jones Ecologists Limited | Professional & scientific | 2019 |
| Grenade Nutrients Limited | Other services | 2022 |
| Grennig Limited | Administrative & support | 2011 |
| Grenview Ltd | Transport & logistics | 2022 |
| Grey Distribution and Training Ltd | Extraterritorial | 2016 |
| Grey Enterprizes Limited | Extraterritorial | 2012 |