| Kj's Motor Car Engineers Limited | Wholesale & retail | 2005 |
| KKS Brothers Ltd | Real estate | 2025 |
| KL Witney Properties Ltd | Real estate | 2025 |
| Klass Cleaning Limited | Administrative & support | 2025 |
| Kleidox Therapeutics Ltd | Professional & scientific | 2020 |
| Klesira Ltd | Professional & scientific | 2025 |
| Klinisker Limited | Health & social care | 2004 |
| KLM Chauffeurs Ltd | Transport & logistics | 2013 |
| Klobucar Medical Limited | Health & social care | 2016 |
| Klug Properties Limited | Real estate | 2018 |
| KM Builders Oxford Ltd | Construction | 2021 |
| KM General Construction Ltd | Manufacturing | 2025 |
| KM Physiotherapy Ltd | Other services | 2026 |
| KM360 CIC | Education | 2025 |
| KMC Holdings (Oxford) Ltd | Real estate | 2022 |
| KMC Property Solutions Ltd | Real estate | 2016 |
| Kmzt Ltd | Health & social care | 2024 |
| KN Property Oxford Limited | Real estate | 2024 |
| Knead ME Limited | Hospitality | 2016 |
| Knell Lane Limited | Professional & scientific | 2013 |
| Knez Investments Limited | Real estate | 2002 |
| Knight Anaesthesia Ltd | Health & social care | 2021 |
| Knights Builders Oxford Ltd | Construction | 2019 |
| KNIT2TOGETHER Limited | Manufacturing | 2020 |
| Knowlden Property Company Ltd | Real estate | 2021 |
| Knowledge E UK Ltd | Information & communication | 2017 |
| Knox - Wells Enterprises Ltd | Hospitality | 2021 |
| KOC Plumbers Limited | Construction | 2020 |
| Koelling Limited | Information & communication | 2013 |
| Kona Muswell Ltd | Wholesale & retail | 2021 |
| Kona Oxford Ltd | Wholesale & retail | 2019 |
| Koogen Limited | Professional & scientific | 2016 |
| Kopitiam & Bar Limited | Hospitality | 2021 |
| Koralli Ltd | Professional & scientific | 2023 |
| Koris Housing Ltd | Real estate | 2019 |
| Koris Management Limited | Professional & scientific | 2015 |
| Korner OX1 Ltd | Hospitality | 2025 |
| Korpu Building Bridges With the Word Ltd | Education | 2018 |
| Kortica Capital Partners Limited | Professional & scientific | 2022 |
| Kortica Holdings Limited | Financial services | 2025 |
| Kortsiide Ltd | Wholesale & retail | 2022 |
| Koto Restaurants Ltd | Hospitality | 2014 |
| Kovner Limited | Transport & logistics | 2015 |
| Koyasan Limited | Professional & scientific | 2024 |
| Krebs Gardens Limited | Households | 2010 |
| Krishan&Co Limited | Transport & logistics | 2025 |
| Kristal Clear Cleaning Company Ltd | Administrative & support | 2015 |
| Kronosldn Limited | Wholesale & retail | 2024 |
| KRS Family Ltd | Real estate | 2023 |
| KS Futures Limited | Financial services | 2008 |
| Ks-Digit Limited | Professional & scientific | 2026 |
| Kserve Limited | Other services | 2026 |
| KSK Oxford Ltd | Professional & scientific | 2026 |
| Kslo Limited | Real estate | 2011 |
| Ktkservices Ltd | Construction | 2021 |
| KTM Scaffolding Limited | Administrative & support | 2010 |
| Kuba Ltd | Professional & scientific | 2006 |
| Kuchnia Domowa - Polish Cuisine Ltd | Hospitality | 2016 |
| Kudos Gratis Ltd | Professional & scientific | 2024 |
| Kulsa CIC | Professional & scientific | 2025 |
| Kulture OX3 Limited | Hospitality | 2024 |
| Kurdchai Limited | Hospitality | 2025 |
| Kuumba NIA Arts | Arts & recreation | 2009 |
| KVS Consulting Ltd | Information & communication | 1998 |
| Kwazi Sports Group Ltd | Professional & scientific | 2025 |
| KWZ Retailers Ltd | Wholesale & retail | 2025 |
| Kyiv Roses Ltd | Professional & scientific | 2025 |
| Kyoto Fusioneering UK Ltd. | Professional & scientific | 2021 |
| Kyropoulos Coaching and Training Ltd | Education | 2025 |
| KZL Solutions Ltd | Professional & scientific | 2025 |
| L & M Diamond Cutting Services Limited | Construction | 2012 |
| L B'S Catering Limited | Hospitality | 2003 |
| L C Scaffolding Limited | Construction | 2015 |
| L C W Electrical Services Ltd | Construction | 2014 |
| L J Macgregor Electricals Ltd | Construction | 2021 |
| L M N Properties Limited | Real estate | 2014 |
| L S Electrical Services (Oxford) Ltd | Construction | 2021 |
| L&B Partners Limited | Professional & scientific | 2019 |
| L&C Bordeanu Services Ltd | Transport & logistics | 2026 |
| L&D Eco Clening Limited | Administrative & support | 2025 |
| L&M Lawrence Ltd | Real estate | 2020 |
| L&P Global Trading Ltd | Wholesale & retail | 2015 |
| L&R Electrical Installations Ltd. | Construction | 2017 |
| L.M.A (Oxford) Limited | Real estate | 2022 |
| L.R.M (Oxford) Limited | Real estate | 2022 |
| LA Bella Bellezza Limited | Other services | 2024 |
| LA Belleza KK Ltd | Other services | 2017 |
| LA Casa DE Dios Limited | Real estate | 2026 |
| LA Dolce Vita Cafe Oxford Ltd | Hospitality | 2024 |
| LA Rustika Ltd | Wholesale & retail | 2018 |
| LA Source Ltd | Professional & scientific | 2025 |
| La'Mercia Care Limited | Health & social care | 2024 |
| LAB for New Knowledge and an Eco-Social Future Community Interest Company | Education | 2017 |
| LAB of Misfits Limited | Professional & scientific | 2012 |
| Lablontechnologies Limited | Information & communication | 2020 |
| Laboratory Animals Limited | Information & communication | 1967 |
| Labour Pump Company Limited | Extraterritorial | 1937 |
| Labsquare Ltd | Wholesale & retail | 2019 |
| LAD Healthcare Ltd | Health & social care | 2018 |
| Ladder Hill Management Company Limited | Households | 1991 |