| Garnet Court (Management) Limited | Households | 1976 |
| Garreg Lwyd Limited | Information & communication | 2011 |
| Gary Smith (Plumbing and Heating) Limited | Construction | 2014 |
| Gateway Family Mediation Ltd | Other services | 2018 |
| Gavan Limited | Wholesale & retail | 2018 |
| Gearing UP UK Ltd | Construction | 2023 |
| Gembo-Tique Limited | Wholesale & retail | 2023 |
| Geoff Searing Consultancy Limited | Professional & scientific | 2008 |
| Geoff Tinsley Ltd | Professional & scientific | 2007 |
| Geomarine Consultants Limited | Professional & scientific | 2014 |
| Geometry Properties Limited | Real estate | 1986 |
| Geotechnical and Environmental Consulting Limited | Construction | 2007 |
| Getaway Digital Limited | Administrative & support | 2001 |
| Gimblett Hardware Limited | Wholesale & retail | 2002 |
| Girl Time Limited | Information & communication | 2012 |
| Gladio Limited | Financial services | 2015 |
| Glamplands Ltd | Extraterritorial | 2022 |
| Glen Court (Weymouth) Limited | Households | 1992 |
| Glitched Toys and Collectibles Ltd | Wholesale & retail | 2024 |
| Global Awarding Education | Education | 2019 |
| Global Marine Solutions Ltd | Professional & scientific | 2018 |
| Globalstore Weymouth Ltd | Wholesale & retail | 2024 |
| Globegood Limited | Households | 1984 |
| Gloucester Lodge Limited | Households | 2001 |
| GMR Human Performance Limited | Professional & scientific | 2021 |
| GMS Plumbing & Heating Supplies Ltd | Wholesale & retail | 2010 |
| GNS Property Limited | Construction | 2016 |
| Go Gourmet Limited | Hospitality | 2016 |
| Goathorn Precision Engineering Limited | Professional & scientific | 2019 |
| Goldcrest Foods Limited | Manufacturing | 2004 |
| Goldcrest Jewellers Limited | Wholesale & retail | 2009 |
| Golden Bridge Weymouth Ltd | Hospitality | 2025 |
| Golden Key (Weymouth) Limited | Real estate | 1971 |
| Goldstead Properties Ltd | Real estate | 2025 |
| Goldstone Property Management Ltd | Hospitality | 2024 |
| Golf Matters Limited | Wholesale & retail | 2019 |
| Good AS Gold Jewellers Limited | Wholesale & retail | 2012 |
| Good Move Lettings Limited | Real estate | 2017 |
| Goodsell Systems Limited | Information & communication | 2000 |
| Governance and Compliance Solutions Ltd | Professional & scientific | 2025 |
| Government and Opposition Limited | Information & communication | 1965 |
| Gradient Support Services Ltd | Transport & logistics | 2018 |
| Graham Bailey Engineering Limited | Manufacturing | 2025 |
| Granary Wharf Management Company Limited | Households | 1987 |
| Granby Roofing and Building Supplies Ltd | Wholesale & retail | 2004 |
| Grapevine Direct Ltd | Wholesale & retail | 2022 |
| Gravy Boat Catering LLP | | 2018 |
| Grays Project Management Services Limited | Information & communication | 1998 |
| Great Western Homes Ltd | Real estate | 2025 |
| Green & Holmes Ltd | Professional & scientific | 2026 |
| Green Light Driving Limited | Education | 2026 |
| Greenfield Enquiries Ltd | Administrative & support | 2025 |
| Greenhill Commercial Limited | Wholesale & retail | 2013 |
| Greenhill Community Trust C.I.C. | Arts & recreation | 2018 |
| Greenhill Heights Management Company Limited | Households | 2001 |
| Greenhill Industrial Holdings Limited | Financial services | 2013 |
| Greenhill P.M. & Cleaning Limited | Administrative & support | 2017 |
| Greenrise Property Management Limited | Hospitality | 1982 |
| Greg Mudge Limited | Professional & scientific | 2005 |
| Gregg Holdings Limited | Financial services | 2022 |
| Grey Ranks Boxing Club Limited | Arts & recreation | 2021 |
| Greystoke Penrith Freehold 57 Ltd | Real estate | 2024 |
| Greystoke Penrith Leasehold 57 Ltd | Real estate | 2024 |
| Griffiths Sales Limited | Administrative & support | 2025 |
| Groundscape Dorset Ltd | Administrative & support | 2023 |
| Group Scaffolding Limited | Construction | 2023 |
| Grove Farm Estates Limited | Real estate | 2019 |
| Groves Malthouse Freehold Limited | Real estate | 2004 |
| GRP and Marine Limited | Manufacturing | 2021 |
| GSR Estates Limited | Real estate | 2017 |
| Guardians of the Old Town Hall Community Interest Company | Arts & recreation | 2009 |
| Gulliver Consultations Ltd | Professional & scientific | 2025 |
| GUS Holdings Dorset Limited | Financial services | 2016 |
| Gutterfix Ltd | Construction | 2013 |
| Guyett Construction Ltd | Construction | 2025 |
| GW GAS & Heating Solutions Limited | Construction | 2016 |
| GWT Estates Limited | Real estate | 2015 |
| GXG Estates Limited | Real estate | 2016 |
| Gym Geek Dorset Limited | Other services | 2022 |
| Gym Geek Online Ltd | Arts & recreation | 2021 |
| H&M Properties (Dorset) Limited | Hospitality | 2026 |
| H&Y Chinese Ltd | Hospitality | 2022 |
| H. E. Box Limited | Wholesale & retail | 1978 |
| H/T Portland Limited | Manufacturing | 2012 |
| Hagley Haulage Ltd | Transport & logistics | 2026 |
| Hair Raizzing Limited | Other services | 2003 |
| Haith Ltd | Hospitality | 2025 |
| Halcyon Extra Limited | Wholesale & retail | 2017 |
| Haley Court Management Company Limited | Households | 1989 |
| Halsail Ltd | Information & communication | 2021 |
| Halvette Limited | Households | 2022 |
| HAM House Leasehold 57 Ltd | Real estate | 2024 |
| Hamamy Limited | Real estate | 2015 |
| Hamilton Hideaways Ltd | Hospitality | 2021 |
| Hampson Builders Limited | Construction | 2017 |
| Hampson House Limited | Hospitality | 2024 |
| Handpicked Shellfish Company Limited | Agriculture & fishing | 2004 |
| Hands on Hobbies Ltd | Wholesale & retail | 2025 |
| Hapi Holdings Ltd | Households | 2024 |
| Happy Home Mortgages Ltd | Financial services | 2017 |