| Gregory Surveyors Ltd | Other services | 2020 |
| Grendburg Supplies Ltd | Information & communication | 2022 |
| Grey Matters TOO Ltd | Education | 2025 |
| Greystones GEO Ltd | Professional & scientific | 2019 |
| Grid SET Ltd | Professional & scientific | 2005 |
| Griffin Enterprises Limited | Administrative & support | 2009 |
| Griffins Financial Solutions Limited | Financial services | 1980 |
| Grill House Takeaway Ltd | Hospitality | 2020 |
| Grimebusters (Oxford) Ltd | Professional & scientific | 2000 |
| Grip:Seven Ltd | Manufacturing | 2018 |
| Grosvenor Motor Company Limited | Wholesale & retail | 1999 |
| Grosvenor Trustees Limited | Administrative & support | 1983 |
| Ground Rent Investors Limited | Real estate | 2009 |
| Ground UP Engineering Limited | Mining & quarrying | 2011 |
| Groundhog IT Consulting Ltd | Information & communication | 2020 |
| Groundwater Monitoring & Drilling Limited | Construction | 2003 |
| Group Life Community Interest Company | Education | 2024 |
| Group Savvy Limited | Financial services | 2019 |
| Groups App Ltd | Information & communication | 2024 |
| Grouse&Company Ltd | Manufacturing | 2025 |
| Grove Court (Iffley) Limited | Real estate | 1975 |
| Grovelands UK Limited | Real estate | 2003 |
| Growing Good Technology Limited | Information & communication | 2022 |
| Grumpy Foods Limited | Hospitality | 2023 |
| Grupo Temple Ltd | Financial services | 2023 |
| GS11 Ltd | Transport & logistics | 2025 |
| GSR PVT Ltd | Professional & scientific | 2025 |
| GT Insurance Services Ltd | Financial services | 2020 |
| GT Services Oxford Ltd | Administrative & support | 2020 |
| GTC Design & Build Limited | Construction | 2018 |
| GTE Properties Ltd | Real estate | 2025 |
| GTW Media Limited | Information & communication | 2012 |
| Guardian Patios and Landscaping Ltd | Administrative & support | 2026 |
| Guarding UK Security Services Limited | Administrative & support | 2019 |
| Gudmen Ltd | Wholesale & retail | 2023 |
| Guest Marketing Services Limited | Professional & scientific | 2013 |
| Guild Ltd | Financial services | 2024 |
| Guildstone Property Services Limited | Construction | 2024 |
| Guillogs Limited | Professional & scientific | 2023 |
| Guled Services Ltd | Professional & scientific | 2024 |
| Gulzar Holdings Limited | Administrative & support | 2021 |
| Gumtree Management Services Limited | Professional & scientific | 2017 |
| Guppy Publishing Ltd | Information & communication | 2018 |
| Guri Enterprises Ltd | Real estate | 2022 |
| GUT Feel Ltd | Professional & scientific | 2023 |
| GUT Wealth Group Ltd | Education | 2022 |
| GUY Court Freehold Limited | Households | 2020 |
| GUY Court Residents Association Limited | Households | 1978 |
| Guydens Hamlet Management Limited | Households | 2015 |
| GV Wood Production Ltd | Manufacturing | 2018 |
| GW Tech Ltd | Information & communication | 2012 |
| GY Tiles Limited | Wholesale & retail | 2025 |
| Gymnag Ltd | Information & communication | 2007 |
| Gynaecology Care Oxford Limited | Health & social care | 2018 |
| Gyoza & Bento Oxford Limited | Hospitality | 2024 |
| Gyst Well-Being Ltd | Professional & scientific | 2021 |
| H & M (London) Property Limited | Real estate | 2023 |
| H & S Invespro Limited | Real estate | 2023 |
| H & S Logistik Ltd | Transport & logistics | 2025 |
| H D Communications Limited | Professional & scientific | 2007 |
| H N B Engineering Services Ltd | Construction | 2024 |
| H&A Beauty Supplies Limited | Wholesale & retail | 2025 |
| H&H Handyman Oxfordshire Ltd | Construction | 2023 |
| H&Sc Technologies Limited | Information & communication | 2014 |
| H&Y Consultancy Ltd | Real estate | 2025 |
| H.Burden Pension Trustees Limited | Extraterritorial | 2004 |
| H.F.N.Properties Limited | Real estate | 2023 |
| H2R2 Limited | Professional & scientific | 2009 |
| H4 Partnership Ltd | Financial services | 2025 |
| H4P Consult Ltd | Professional & scientific | 2024 |
| H4P Projects Ltd | Professional & scientific | 2024 |
| Habitancy Limited | Administrative & support | 2019 |
| Habitar Architects Limited | Professional & scientific | 2013 |
| Hacienda Property Corporation Limited | Households | 2022 |
| Hacking Consulting Company Ltd | Health & social care | 2010 |
| Hadar Homes Ltd | Real estate | 2022 |
| Haddie Plumbing and Utilities Ltd | Construction | 2026 |
| Hadfield Consultants Ltd | Professional & scientific | 2011 |
| Hadithi Baskets Limited | Education | 2025 |
| Hafren Resourcing Ltd | Administrative & support | 2010 |
| Hagn Limited | Real estate | 2024 |
| Haiji Tea Limited | Wholesale & retail | 2025 |
| Hailey Public House Limited | Hospitality | 2019 |
| Hailmac Limited | Real estate | 1970 |
| Haines General Builders Limited | Construction | 2024 |
| Hairkut Ltd. | Information & communication | 2021 |
| Haiwear Limited | Wholesale & retail | 2023 |
| HAK Property Limited | Real estate | 2020 |
| Hale Property Solutions Ltd | Real estate | 2026 |
| Halgabron Asset Management Company Limited | Hospitality | 2021 |
| Hall,The Printer,Limited | Manufacturing | 1913 |
| Hallaby Ltd | Information & communication | 2024 |
| Haller Enterprises Limited | Construction | 2015 |
| Halley Café Limited | Hospitality | 2020 |
| Halley Group GB Limited | Financial services | 2020 |
| Halley Studios Limited | Education | 2020 |
| Hallidays Developments Limited | Construction | 2007 |
| Halls Oxford Limited | Hospitality | 2009 |
| Halo Circle Ltd | Construction | 2016 |
| Halsa Consulting Limited | Health & social care | 2011 |