| Weymouth Museum Trust | Arts & recreation | 2010 |
| Weymouth Nails & Spa Limited | Other services | 2025 |
| Weymouth Pharma Ltd | Wholesale & retail | 2022 |
| Weymouth Pianos Limited | Manufacturing | 2014 |
| Weymouth Piri Piri Ltd | Hospitality | 2021 |
| Weymouth Plumbing and GAS Services Ltd | Construction | 2012 |
| Weymouth Powerboat Training Limited | Education | 2026 |
| Weymouth Precision Engineers Limited | Manufacturing | 2012 |
| Weymouth Precision Holdings Ltd | Financial services | 2020 |
| Weymouth Quality Engineering Limited | Manufacturing | 2001 |
| Weymouth Restaurant Ltd | Hospitality | 2023 |
| Weymouth Saint Paul Trading Co. Limited | Wholesale & retail | 1998 |
| Weymouth Services Ltd | Professional & scientific | 2022 |
| Weymouth Shellfish Charter's Ltd | Transport & logistics | 2024 |
| Weymouth Sun Limited | Hospitality | 2021 |
| Weymouth Tyres Ltd | Wholesale & retail | 2025 |
| Weymouth Vehicle Repair Centre Ltd | Wholesale & retail | 2024 |
| Weymouth's Favourite MR Whippy Ltd | Wholesale & retail | 2023 |
| WGC Golf TEE Limited | Arts & recreation | 2022 |
| What Path to Take Limited | Extraterritorial | 2026 |
| Wheres Good?! Ltd | Professional & scientific | 2024 |
| Whetham & Leake Limited | Manufacturing | 2005 |
| Whiskers KP Limited | Information & communication | 2025 |
| White House Aviation Limited | Administrative & support | 2003 |
| White Sails Management Company Limited | Extraterritorial | 2013 |
| White Stones Developments Ltd | Real estate | 2019 |
| Whitehead-Ross Social Work Ltd | Health & social care | 2018 |
| Whitehorse Leadership Training Ltd | Other services | 2002 |
| Whitesand Properties Limited | Real estate | 2006 |
| Wickenden Analytics Ltd | Professional & scientific | 2023 |
| Wide Street Motors Limited | Wholesale & retail | 2025 |
| Wild Garlic (Poole) Limited | Wholesale & retail | 2021 |
| Wild Oak Group Ltd | Hospitality | 2008 |
| Wild Oak Property Ltd | Real estate | 2022 |
| Wild Oyster Holiday Homes Ltd | Hospitality | 2021 |
| Wild Times Fitness Ltd | Arts & recreation | 2015 |
| Wild White Media Limited | Professional & scientific | 2017 |
| Wildfire Design Limited | Information & communication | 2005 |
| Wildwood Arborists Ltd | Agriculture & fishing | 2025 |
| William Hyde Ltd | Households | 2012 |
| Willow Cottage Gardening Limited | Administrative & support | 2014 |
| Willow Property Developers UK Ltd | Real estate | 2025 |
| Wilson Tominey Financial Services LP | | 2009 |
| Wilson Tominey Lettings LP | | 2009 |
| Wilson Tominey Parsons Group LP | | 2009 |
| Wilsons Craft Distillery Limited | Manufacturing | 2025 |
| Wiltshire and Somerset Psychology Ltd | Health & social care | 2024 |
| Wind and Tide Services Limited | Construction | 2016 |
| Window World Weymouth Ltd | Construction | 2015 |
| Winfrith Animal Sanctuary Limited | Other services | 2023 |
| Winfrith Hedgehog Wildlife Sanctuary Ltd | Other services | 2016 |
| Wingage Limited | Extraterritorial | 2009 |
| Wink Money Limited | Financial services | 2021 |
| Winstrongstrengthandconditioning Limited | Other services | 2023 |
| Winter Holdings Limited | Professional & scientific | 2018 |
| Wishbone Holdings Ltd | Administrative & support | 2025 |
| Woke! the Opera Limited | Arts & recreation | 2024 |
| Wokingham Convenience Store Ltd | Wholesale & retail | 2021 |
| Woodlows Limited | Real estate | 1953 |
| Woodlows Properties Limited | Real estate | 2010 |
| Woodpecker Properties Limited | Real estate | 1993 |
| Woodruff Key Consulting Limited | Information & communication | 2014 |
| Woodshed Properties Limited | Real estate | 2019 |
| Work on Water Limited | Wholesale & retail | 2007 |
| WPD Building Services Limited | Construction | 2026 |
| WPD Services SW Ltd | Construction | 2025 |
| Wpmd Ltd | Information & communication | 2011 |
| Wrap BEE UP Limited | Manufacturing | 2021 |
| Write and Delight PVT Ltd | Wholesale & retail | 2026 |
| Writecombination Ltd | Information & communication | 2011 |
| Wynchard Limited | Professional & scientific | 2015 |
| Wyvern Fireplaces Limited | Wholesale & retail | 2015 |
| Xenon Radio Ltd | Information & communication | 2026 |
| Xtraordinary-Life Ltd. | Professional & scientific | 1999 |
| Yado Ltd | Real estate | 2016 |
| Yard Retailers Limited | Wholesale & retail | 2010 |
| Yellow Collective Ltd | Manufacturing | 2023 |
| YMT Sales Limited | Transport & logistics | 2012 |
| York Homes (Dorset) Limited | Health & social care | 1987 |
| YOU ARE the Moment Ltd | Arts & recreation | 2025 |
| Your Local ALE House Ltd | Hospitality | 2024 |
| Z & N Healthcare Limited | Health & social care | 2013 |
| Zanade Locum Company Limited | Health & social care | 2007 |
| ZEN CNC Ltd | Manufacturing | 2024 |
| Zenith Improvement Partners Ltd | Education | 2018 |
| Zest, Joy and Spirit Ltd | Administrative & support | 2023 |
| Zingaro Solutions Limited | Information & communication | 1997 |
| ZOE Withers Ltd | Administrative & support | 2007 |
| Zoey Court 1994 Limited | Households | 1994 |
| Zone Weymouth Limited | Arts & recreation | 2017 |
| Zoom Marketing South Ltd | Professional & scientific | 2025 |