| Level UP Leadership Ltd | Professional & scientific | 2026 |
| Level UP Marketing Solutions Limited | Administrative & support | 2017 |
| Levson Gtech UK Limited | Wholesale & retail | 2023 |
| Lexonis Ltd | Professional & scientific | 2010 |
| Leybob Medical Limited | Health & social care | 2021 |
| Leyland Powertrain Limited | Manufacturing | 2021 |
| LFG Aviation Ltd | Transport & logistics | 2024 |
| LHY Powertrain Limited | Manufacturing | 1970 |
| Libra Transport Ltd | Transport & logistics | 2019 |
| Library Performance Measurement Conference CIC | Administrative & support | 2020 |
| Lifespan Healthcare Ltd | Health & social care | 2025 |
| Lighthouse Worldwide Solutions UK Ltd | Manufacturing | 2023 |
| Lightning Electrical Solutions Ltd | Manufacturing | 2021 |
| Lilac Assets Management Ltd | Real estate | 2020 |
| Lili Mohiddin Consultancy Ltd | Administrative & support | 2024 |
| Lilwood Ltd | Real estate | 2018 |
| Lilypad Sourcing & Investments Ltd | Real estate | 2025 |
| Limb Reconstruction and Infection Consultancy Limited | Health & social care | 2019 |
| Limetec Limited | Manufacturing | 2015 |
| LIN Marsh Music Limited | Education | 2002 |
| Lindsay Whittam Dermatology Limited | Health & social care | 2019 |
| Lingda Education Ltd | Education | 2024 |
| Linq Immigration Ltd | Professional & scientific | 2023 |
| Liramo Limited | Professional & scientific | 2006 |
| Lisa’S Nail Ltd | Other services | 2024 |
| Listan Publications Limited | Information & communication | 1947 |
| Lister Construction Management Ltd | Professional & scientific | 2009 |
| Lite Link Technology Limited | Information & communication | 2025 |
| Litehouse Europe Limited | Wholesale & retail | 2008 |
| Litering Ltd | Professional & scientific | 2012 |
| Little Angels Childcare Group Limited | Education | 2018 |
| Little Hedgehogs Limited | Education | 2004 |
| Little Indya Global Trading Limited | Wholesale & retail | 2017 |
| Littlemore Rugby Football Club Limited | Administrative & support | 2018 |
| Live Oxford Limited | Construction | 2010 |
| Liveres Limited | Information & communication | 2010 |
| Livewire U.K. Ltd. | Wholesale & retail | 2022 |
| Living Alfresco Ltd | Wholesale & retail | 2020 |
| Living Optics Limited | Manufacturing | 2019 |
| Lizkni Ltd | Professional & scientific | 2013 |
| Lizzi Zarowski Weddings Ltd | Other services | 2024 |
| LJS Administrative Services Limited | Professional & scientific | 2023 |
| LJS Landscaping Limited | Construction | 2020 |
| LM GAS Services Limited | Construction | 2017 |
| LM Roofing Abingdon Ltd | Construction | 2021 |
| Logan Telecom Group Limited | Information & communication | 2021 |
| Lokstrom Investments Ltd | Real estate | 2019 |
| Londis Marciano Limited | Wholesale & retail | 2025 |
| London & Oxford Trustees Limited | Professional & scientific | 2000 |
| London Brunel International College Limited | Education | 2004 |
| London Road (Oxford) Limited | Real estate | 2011 |
| London School of Business English Ltd | Education | 2013 |
| Long Furlong Healthcare LLP | | 2015 |
| Longfellow 1973 Limited | Extraterritorial | 2014 |
| Longtoo Limited | Wholesale & retail | 2021 |
| Longwall Security (Dach) Limited | Financial services | 2020 |
| Longwall Security Limited | Administrative & support | 2013 |
| Longworth Consulting Ltd | Administrative & support | 2015 |
| Longworth House North Estate Management Company Limited | Households | 1994 |
| Lorien 7 Limited | Information & communication | 2016 |
| Louisrei Ltd | Information & communication | 2023 |
| Love Learning Ltd | Education | 1999 |
| Lovejoy Records Ltd | Arts & recreation | 2015 |
| LOW Carbon Strategies Limited | Wholesale & retail | 2006 |
| Lower Farm Storage Limited | Real estate | 2019 |
| Lownslowktchn Limited | Hospitality | 2025 |
| Loyd Consulting Limited | Professional & scientific | 2014 |
| Loyinum Ltd. | Hospitality | 2019 |
| LPC Carpenrty Ltd | Manufacturing | 2025 |
| LRG Automation Ltd | Manufacturing | 2024 |
| LSA Boilers and Bathrooms Ltd | Construction | 2026 |
| Lsve Services Limited | Construction | 2018 |
| LTI Metaltech Limited | Manufacturing | 2004 |
| Luchi Care Services Ltd | Health & social care | 2020 |
| Lucky Busker Limited | Arts & recreation | 2007 |
| Lucumo Limited | Information & communication | 2026 |
| Lucy Claire Illustration Ltd | Arts & recreation | 2023 |
| Lucy Shepherd Limited | Information & communication | 2020 |
| Luke Bowers Limited | Other services | 2015 |
| Lumina Radiology Ltd | Health & social care | 2026 |
| Luminoso Foods Limited | Hospitality | 2015 |
| Lunar Properties Oxford Ltd | Real estate | 2021 |
| Luttrell Productions Limited | Information & communication | 2004 |
| Luxury British Design 1 Limited | Professional & scientific | 2017 |
| Luxury British Design 2 Limited | Professional & scientific | 2017 |
| Luxury British Design Holdings Limited | Professional & scientific | 2017 |
| Lyon & Associates Ltd | Other services | 2023 |
| M & a House Repair Ltd | Construction | 2025 |
| M a Hones Ltd | Agriculture & fishing | 2008 |
| M G Property (Oxford) Limited | Real estate | 2023 |
| M J Green Properties Ltd | Real estate | 2016 |
| M T Consulting Limited | Professional & scientific | 2000 |
| M Tutty Plumbing and Heating Ltd Ltd | Construction | 2025 |
| M&D Homes Ltd | Real estate | 2025 |
| M. Mildenhall Limited | Construction | 1978 |
| M.G.Car Club Limited(The) | Other services | 1969 |
| M55 Safety Distribution Ltd | Transport & logistics | 2023 |
| M:M BIO Global Incubator Limited | Professional & scientific | 2023 |
| M:M BIO Global Services Limited | Professional & scientific | 2023 |
| M:M BIO Limited | Professional & scientific | 2021 |