| K30 Interior Contracts Limited | Construction | 2018 |
| Kaizen Platforms Ltd | Manufacturing | 2022 |
| Kaluzny R&D Limited | Professional & scientific | 2014 |
| Kaplan's Cafe & Bistro Ltd | Hospitality | 2015 |
| Kaplan's Cafe (Coleford) Ltd | Hospitality | 2015 |
| Kear & KU Ltd | Wholesale & retail | 2010 |
| Kenley House Management Company Limited | Real estate | 2003 |
| Kevins Butchers(Mitcheldean) Ltd | Wholesale & retail | 2011 |
| Keystone Forest Homes Ltd | Real estate | 2026 |
| KHD Property Limited | Real estate | 2023 |
| Kiely Carpets Limited | Wholesale & retail | 1996 |
| Kiely Developments Limited | Construction | 2024 |
| Kingsdean Sheepdogs Ltd | Other services | 2021 |
| KJT Residential Lydney Ltd | Real estate | 2014 |
| Kltrades Ltd | Wholesale & retail | 2021 |
| Knight's Interiors (KBB) Ltd | Construction | 2020 |
| Kraszewski Developments Ltd | Administrative & support | 2013 |
| KSK Hair Academy Ltd | Other services | 2025 |
| L B & C B Taylor Limited | Construction | 2008 |
| L30 MTB Limited | Other services | 2022 |
| LA Belle Boite Ltd | Other services | 2015 |
| LA Mangia Ltd | Hospitality | 2025 |
| Ladybug Pest Control Limited | Agriculture & fishing | 2018 |
| Lagom Limited | Other services | 2009 |
| Lanc Properties Ltd | Real estate | 2025 |
| Lancestar Properties Limited | Real estate | 2000 |
| Land Agents Limited | Professional & scientific | 2011 |
| Lange Limited | Real estate | 2017 |
| Langfield Technologies Limited | Professional & scientific | 1995 |
| Lavender's Holdings Limited | Financial services | 2017 |
| Lavender's Property Limited | Real estate | 2017 |
| Lazy Bear Ltd | Administrative & support | 2023 |
| Leachwin Technology Limited | Information & communication | 2014 |
| LEE Price EFW Consultancy Ltd | Water & waste | 2018 |
| Leetronics Ltd | Manufacturing | 2004 |
| Legge Construction Limited | Construction | 2015 |
| Leisure Pods Ltd | Manufacturing | 2010 |
| LEO Property Ltd | Real estate | 2020 |
| Level N Ltd | Information & communication | 2003 |
| Lifeskill's, Integration, Flexibility and Empowerment Services Ltd | Health & social care | 2015 |
| Light Fantastic DIY Limited | Wholesale & retail | 2011 |
| Light Fantastic Hardware Limited | Wholesale & retail | 2021 |
| Lighthouse Properties (Glos) Limited | Real estate | 2015 |
| Linked-Learning Ltd | Education | 2023 |
| Lioned Limited | Construction | 1987 |
| LJP & Co Limited | Professional & scientific | 2013 |
| Lobi Patisserie Cafe Ltd | Hospitality | 2026 |
| Local Business Rocks Ltd | Other services | 2020 |
| Lodge Picture Framing Limited | Professional & scientific | 2022 |
| London BUS Promotions Limited | Administrative & support | 2009 |
| Lrhj Group Ltd | Manufacturing | 2019 |
| Lrmv Removal Limited | Transport & logistics | 2023 |
| Lucc Ltd | Construction | 2026 |
| Lydney & District Angling Club Limited | Arts & recreation | 2012 |
| Lydney Bathrooms Limited | Wholesale & retail | 2000 |
| Lydney Dial-A-Ride & Community Transport | Transport & logistics | 1991 |
| Lydney Engineering Co. Limited | Energy | 1969 |
| Lydney Friends Limited | Hospitality | 2020 |
| Lydney Harbour Cafe Ltd | Hospitality | 2017 |
| Lydney Land Resources Limited | Real estate | 1999 |
| Lydney Management Company Limited | Professional & scientific | 1993 |
| Lydney Securities Limited | Professional & scientific | 2009 |
| Lydney Skip Hire Ltd | Water & waste | 2017 |
| Lydney Tyre & Auto Services Limited | Wholesale & retail | 2000 |
| Lynwood Car Hire Ltd | Transport & logistics | 2019 |
| Lynwood Electrical Solutions Ltd | Construction | 2024 |
| M & J Horse Transport Ltd | Other services | 2019 |
| M J Security (UK) Limited | Administrative & support | 2003 |
| M J Taylor Plumbing Solutions Ltd | Construction | 2016 |
| M&D Knowles Ltd | Construction | 2020 |
| M. C. Walker Limited | Professional & scientific | 1987 |
| M. E. Damsell Limited | Manufacturing | 2021 |
| Maccas FAM Limited | Wholesale & retail | 2019 |
| Makalex Ltd | Wholesale & retail | 2024 |
| Makula Ltd | Manufacturing | 2015 |
| Maple (224) Limited | Households | 2004 |
| Maple Tree Hill Limited | Real estate | 2024 |
| Mapledean Construction Ltd. | Construction | 2006 |
| Mapledean Homes Limited | Construction | 2010 |
| Marina Motors Group Ltd | Manufacturing | 2018 |
| Mark Evans Transport Limited | Transport & logistics | 2014 |
| Mark LEE Decorating Limited | Construction | 2021 |
| Mark Leonard Transport Ltd | Transport & logistics | 2013 |
| Mark Lumley Blacksmiths Limited | Manufacturing | 2013 |
| Marketing Partners Services Ltd | Professional & scientific | 2003 |
| Martin Tremayne Transport Limited | Transport & logistics | 2015 |
| Matrix Accounts Taxation & Payroll Limited | Professional & scientific | 2016 |
| Matthews Design and Development Limited | Real estate | 2024 |
| MAY Hill Tractors Limited | Wholesale & retail | 2015 |
| Mayo Technical Services Limited | Transport & logistics | 2007 |
| Mclellan Design Limited | Professional & scientific | 2018 |
| MCR Post Limited | Information & communication | 2011 |
| Mediamoto Ltd | Professional & scientific | 2019 |
| Mens Designer Discount Sales Ltd | Wholesale & retail | 1998 |
| Merlin Adventures Limited | Education | 2002 |
| Merlin Environmental Services Ltd | Water & waste | 2021 |
| MIA Rose Nurseries Ltd | Education | 2019 |
| Milata Limited | Information & communication | 2025 |
| Miles Cottages Management Company Limited | Households | 1984 |
| Miles Laughton Joinery Limited | Manufacturing | 2011 |