| Greenapap PUB Co Ltd | Hospitality | 2025 |
| Greenbank Bassett Limited | Professional & scientific | 2019 |
| Greenbank Property Lettings Limited | Real estate | 2026 |
| Greenbush Management Company Limited | Households | 1989 |
| Greenbyrd Ltd | Professional & scientific | 2023 |
| Greencote Limited | Health & social care | 2009 |
| Greene Back Limited | Financial services | 2024 |
| Greenempire Ltd | Construction | 2020 |
| Greener Pastures Services Ltd | Administrative & support | 2025 |
| Greener Vistas Ltd | Wholesale & retail | 2023 |
| Greenfield Agrigear Limited | Administrative & support | 2025 |
| Greenglow Electrical Ltd | Energy | 2021 |
| Greenheart Talent Limited | Administrative & support | 2025 |
| Greenictrecycling Ltd | Information & communication | 2021 |
| Greening Campaign CIC | Professional & scientific | 2020 |
| Greenlanes Traffic Management Ltd | Construction | 2018 |
| Greenleaves Psychological Services Ltd | Health & social care | 2019 |
| Greenontee Ltd | Professional & scientific | 2024 |
| Greenride Taxis Ltd | Transport & logistics | 2025 |
| Greens Development Group Limited | Real estate | 2020 |
| Greenscape Property and Plant Ltd | Real estate | 2014 |
| Greenside Signs & Graphics Ltd | Professional & scientific | 2022 |
| Greensleeves Residential Care Home Limited | Health & social care | 2002 |
| Greenspan Projects Ltd | Administrative & support | 2013 |
| Greenspan SWD Ltd | Other services | 2023 |
| Greenspan UK Holdings Ltd | Financial services | 2020 |
| Greenstride Designer Ltd | Wholesale & retail | 2021 |
| Greenstruct Ltd | Manufacturing | 2023 |
| Greenwood Builders and Developments Ltd | Construction | 2020 |
| Gregobims Investment Limited | Transport & logistics | 2022 |
| Gregu Transport Ltd | Transport & logistics | 2014 |
| Grewalservices Limited | Transport & logistics | 2025 |
| Grey Badger Consulting Ltd | Professional & scientific | 2011 |
| Grey Cat Property Limited | Real estate | 2025 |
| Grey Cell Studios Ltd | Professional & scientific | 1990 |
| Grey FOX Property Limited | Real estate | 2020 |
| Grey Photographic Ltd | Professional & scientific | 2015 |
| Grey Spot Ltd | Construction | 2025 |
| Grey Whale Limited | Health & social care | 2022 |
| Greyladyes Arts Foundation | Arts & recreation | 2005 |
| GRG Accountancy Services Ltd | Professional & scientific | 2010 |
| Grickey Ltd | Administrative & support | 2025 |
| Gridpay Networks Ltd | Energy | 2025 |
| Grieg-Mitchell Securities Limited | Administrative & support | 1959 |
| Griffder Ltd | Hospitality | 2017 |
| Griffin Fire & Training Limited | Administrative & support | 2002 |
| Griffin Fire Protection Limited | Administrative & support | 1996 |
| Griffin Intl. Ltd | Professional & scientific | 2023 |
| Griffin Surveys Ltd | Other services | 2012 |
| Griffon Marine Limited | Manufacturing | 1965 |
| Grill House Shad Ltd | Hospitality | 2026 |
| Grill House Zanko Ltd | Hospitality | 2025 |
| Grim Reaper Yacht Surveys Ltd | Manufacturing | 2026 |
| Grim Tooth Ltd | Manufacturing | 2023 |
| Grindstone Inns Limited | Hospitality | 2026 |
| Grinham Engineering Limited | Professional & scientific | 1998 |
| Grinyer Maintenance Ltd | Construction | 2013 |
| Grip & Growl Ltd | Wholesale & retail | 2025 |
| Grit Agency UK Ltd | Professional & scientific | 2020 |
| Grit Holdings Limited | Administrative & support | 2025 |
| Grit Lettings Ltd | Real estate | 2024 |
| Gritton Ltd | Other services | 2016 |
| GRM Carpentry Limited | Construction | 2003 |
| Grmc Carpentry Limited | Construction | 2019 |
| GRO2 Limited | Administrative & support | 2010 |
| Groakeg Limited | Wholesale & retail | 1977 |
| Groath Limited | Professional & scientific | 2016 |
| Groathurst Limited | Real estate | 1973 |
| Grob Limited | Hospitality | 2025 |
| Grooming Cutts Ltd | Other services | 2023 |
| Grooveburn Facilitation Ltd | Professional & scientific | 2024 |
| Groovygoat Tuition Limited | Administrative & support | 2021 |
| Grosvenor Lodge (Southampton) Management Company Limited | Households | 1984 |
| Grosvenor Lodge Southampton Ltd | Real estate | 2012 |
| Grosvenor Mews (Management) Limited | Households | 1969 |
| Grosvenor Place (Fareham) Management Company Limited | Households | 2009 |
| Grosvenor Riverside Limited | Real estate | 2017 |
| Ground Condition Consultants Ltd | Professional & scientific | 2017 |
| Ground School Guru Ltd. | Education | 2011 |
| Grounded Heart Ltd | Extraterritorial | 2011 |
| Groundscape Environmental Limited | Water & waste | 2016 |
| Group HUG Ventures Ltd | Wholesale & retail | 2020 |
| Grove Consulting Limited | Information & communication | 2026 |
| Grove Court (Southampton) Management Company Limited | Households | 1985 |
| Grove Mansions (Management) Limited | Households | 1958 |
| Grove Mansions Freehold Limited | Real estate | 2004 |
| Grove Mechanical Engineering Ltd | Wholesale & retail | 2019 |
| Grove Mill Residents Company Limited(The) | Real estate | 1979 |
| Grove Platform Holdings Ltd | Information & communication | 2026 |
| Grovely Holdings Ltd | Wholesale & retail | 2021 |
| Grover Holdings Limited | Wholesale & retail | 2004 |
| Grow My Startup Limited | Information & communication | 2015 |
| Grow Vitis Ltd | Agriculture & fishing | 2019 |
| Growfest Community Interest Company | Health & social care | 2019 |
| Growth Cart Global Limited | Information & communication | 2025 |
| GRP Boat Repair Specialists Ltd | Manufacturing | 2013 |
| GRP Tools Limited | Manufacturing | 2006 |
| GRS Fleet Graphics Limited | Manufacturing | 2014 |
| Grundeli Ltd | Hospitality | 2025 |
| Gruvi Limited | Professional & scientific | 2010 |