| Kingston Russell Water Co. Limited | Water & waste | 1994 |
| Kington Property Limited | Construction | 2022 |
| Kinsman Investments Limited | Real estate | 2020 |
| Kinson Pottery Limited | Financial services | 1896 |
| Kitcat Limited | Agriculture & fishing | 1996 |
| Kitchens by Emily Limited | Wholesale & retail | 2017 |
| Kitsack Limited | Wholesale & retail | 2018 |
| KIX Start Community Interest Company | Education | 2014 |
| KL Interior Services Limited | Professional & scientific | 2021 |
| KL Wheeler Ltd | Arts & recreation | 2025 |
| Klaus Boden Limited | Construction | 2019 |
| KLF Security Ltd | Administrative & support | 2021 |
| Kline Construction Ltd | Construction | 2022 |
| Kline Modular Ltd | Construction | 2023 |
| Knighton Countryside Management Limited | Agriculture & fishing | 2004 |
| Knighton Engineering Services Ltd | Professional & scientific | 2023 |
| Knights Mayne Management Limited | Households | 2020 |
| Konstantin Productions Limited | Arts & recreation | 2015 |
| Kooky Bloom Limited | Wholesale & retail | 2023 |
| Koori Limited | Construction | 2006 |
| Kore Pilates Ltd | Arts & recreation | 2025 |
| KOT Building Contractors Limited | Construction | 2024 |
| KOT Events Limited | Arts & recreation | 2015 |
| KRA U.K. Limited | Professional & scientific | 2023 |
| KRG Engineering Ltd | Professional & scientific | 2026 |
| Kristal Detailing Limited | Wholesale & retail | 2025 |
| Kritischer Hase Limited | Information & communication | 2020 |
| Kronos Food Limited | Wholesale & retail | 2020 |
| Krug Auto Intel Limited | Wholesale & retail | 2024 |
| Krzy Vision Ltd | Information & communication | 2024 |
| Kuemme Limited | Wholesale & retail | 2025 |
| KV Dentistry Limited | Health & social care | 2024 |
| KWD Dorset Ltd | Construction | 2022 |
| L & a Bray Limited | Real estate | 2001 |
| L & N Business Planning Ltd | Professional & scientific | 2016 |
| L & P Incorporated Ltd | Real estate | 2024 |
| L C Dorset Groundworks Limited | Construction | 2017 |
| L Construction Ltd | Construction | 2007 |
| L Greenan Limited | Construction | 2015 |
| L J Boreham Ltd | Health & social care | 2022 |
| L of a Car Limited | Wholesale & retail | 2009 |
| LA Grange SUD Limited | Hospitality | 2022 |
| Labooh Investments Limited | Financial services | 2018 |
| Lakeland Medical Services Limited | Health & social care | 2013 |
| Lakeside Vehicle Solutions Ltd | Wholesale & retail | 2024 |
| Langdown Planning Services Ltd | Professional & scientific | 2025 |
| Langham Family Holdings Limited | Financial services | 2018 |
| Langham Industries Limited | Professional & scientific | 1980 |
| Langham Wine Limited | Manufacturing | 2011 |
| Lantern (Weymouth) Trading Company Limited | Wholesale & retail | 2005 |
| Lantern Accounting Ltd | Professional & scientific | 2026 |
| Lantern House Property Management Limited | Households | 2017 |
| Larkham Farm Limited | Agriculture & fishing | 2004 |
| Larkham Limited | Real estate | 2019 |
| Larkrise (Broadstone) Management Co Ltd. | Households | 2008 |
| Lashmania Ltd | Wholesale & retail | 2021 |
| Latent Drive Ltd | Energy | 2020 |
| Latest Thing Limited | Financial services | 2020 |
| Launchpad Dorset CIC | Arts & recreation | 2023 |
| Laurel Designs Ltd | Manufacturing | 2019 |
| Laval Coffee Ltd | Administrative & support | 2011 |
| Laverstock Properties Limited | Construction | 1986 |
| Lawrence Consultancy Ltd | Administrative & support | 2023 |
| Laye Capital Limited | Financial services | 2023 |
| Lazyhill Stores Limited | Wholesale & retail | 2014 |
| LBW Media Limited | Information & communication | 2018 |
| LC Investment Group Limited | Financial services | 2025 |
| LC Vending Limited | Wholesale & retail | 2009 |
| Lcpe Ltd | Manufacturing | 2024 |
| LDF Waite Ltd | Professional & scientific | 2026 |
| Ldnk Limited | Professional & scientific | 2023 |
| LEA Legacy Properties Limited | Construction | 2025 |
| Lead on Dog Services Limited | Wholesale & retail | 2017 |
| Lead on Dog Training Ltd | Education | 2022 |
| Leading Projects Limited | Real estate | 2024 |
| Leaping Lemurs Ltd. | Professional & scientific | 2006 |
| Lederer Limited | Professional & scientific | 2022 |
| LEE Ford IFA Limited | Financial services | 2011 |
| LEE Mitchell Water & Utility Services Ltd | Construction | 2022 |
| Leech Racing Limited | Arts & recreation | 2007 |
| Legacy Care Ltd | Health & social care | 2016 |
| Leggacy Ltd | Real estate | 2023 |
| Leilaloves Ltd | Wholesale & retail | 2023 |
| Lemon Tree Retail Ltd | Wholesale & retail | 2024 |
| Leonard Meadows Management Company Limited | Households | 2020 |
| Lepard & Smiths Limited | Wholesale & retail | 1988 |
| Lester Business Services Limited | Arts & recreation | 2013 |
| Lets Go Supported Holidays Ltd | Health & social care | 2012 |
| Lewis Dean Estate Agents Limited | Real estate | 2017 |
| Lewis Dean Letting Agents Limited | Real estate | 2013 |
| Lewis Palmer Plumbing Limited | Construction | 2002 |
| Lewis Scaffold Solutions Limited | Construction | 2018 |
| Life Sense (Dorset) Ltd | Other services | 2022 |
| Lift Access Solutions Ltd | Administrative & support | 2024 |
| Lift OFF Trading Limited | Wholesale & retail | 2008 |
| Lightwave Trails Ltd | Professional & scientific | 2026 |
| Lily Property Holdings (South) Ltd | Real estate | 2025 |
| Lily Residential Services Ltd | Health & social care | 2021 |
| Lily Services Group Ltd | Financial services | 2026 |
| Lily Staff Solutions Ltd | Administrative & support | 2021 |