| Wi-Sun Alliance Limited | Information & communication | 2013 |
| Wick Hall (Hove) Freehold Limited | Households | 2022 |
| Widehurst Solar Limited | Energy | 2015 |
| WIG Systems Limited | Information & communication | 2025 |
| Wilbees Solar Limited | Energy | 2014 |
| Wilber Developments Limited | Real estate | 2018 |
| Wilbury Estates Ltd | Households | 2019 |
| Wilbury Garages Ltd | Households | 2025 |
| Wilding Design Limited | Professional & scientific | 2019 |
| Will Edwards Limited | Information & communication | 2005 |
| Willett Property Management Ltd | Households | 2022 |
| William Alexander Recruitment Ltd | Administrative & support | 2009 |
| William Latham Productions Ltd | Administrative & support | 2003 |
| William Smith Close (Block a) Freehold Ltd | Households | 2022 |
| William Tucker Kitchens and Carpentry Ltd | Construction | 2019 |
| Williams Builders of Sussex Ltd | Construction | 2013 |
| Williams Electrical Contractors (Southern) Ltd | Construction | 2023 |
| Williams Estate and Letting Agency Limited | Real estate | 2025 |
| Williams Residential (Sussex) Ltd | Hospitality | 2015 |
| Williamson Dental Limited | Health & social care | 2022 |
| Willoughby's Consolidated Public Limited Company | Financial services | 1894 |
| Willow & Daisy Ltd | Hospitality | 2023 |
| Willow & Grey Ltd | Construction | 2021 |
| Willowing Arts Ltd | Arts & recreation | 2013 |
| Wilson & Wilson Holdings Ltd | Financial services | 2022 |
| Wilson Sandford (Hove) Limited | Professional & scientific | 2003 |
| Wilsonpickles Limited | Health & social care | 2024 |
| Wilton House Freehold Company Ltd | Households | 2016 |
| Wilton Solar Farm Limited | Energy | 2011 |
| WIM Delvoye Ltd | Administrative & support | 2013 |
| Wind Energy Solutions Ltd | Information & communication | 2018 |
| Windiesels Ltd | Real estate | 2021 |
| Windlesham Finance Company Limited | Real estate | 1956 |
| Windlesham Hall Limited | Real estate | 1957 |
| Windmill 4 Limited | Real estate | 1997 |
| Windmill 6 Limited | Real estate | 2016 |
| Windmill Construction Brighton Ltd | Construction | 2014 |
| Window Workshop (Sussex) Limited | Construction | 2015 |
| Windrush Partners 2 Ltd | Other services | 2023 |
| Windsor Lodge (Hove) Limited | Households | 1991 |
| Windsteer Consultancy Ltd | Professional & scientific | 2024 |
| Windy Roads Limited | Administrative & support | 2024 |
| Wine Barrel Brighton & Hove Ltd | Wholesale & retail | 2022 |
| Wine Barrel Enterprises Ltd | Wholesale & retail | 2016 |
| Wine Equals Friends Limited | Wholesale & retail | 2000 |
| Winfre Ltd | Professional & scientific | 2025 |
| Wings Creative Ltd | Other services | 2025 |
| Winkworth Dental Limited | Health & social care | 2024 |
| Winn Estates Lettings Ltd | Real estate | 2025 |
| Winn Estates Sales Ltd | Real estate | 2025 |
| Winnards Solar Limited | Energy | 2013 |
| Winter Estates Limited | Real estate | 2020 |
| Wiretouch Ltd | Information & communication | 2011 |
| Wisden Packaging Limited | Manufacturing | 1991 |
| Wisdom Law Limited | Professional & scientific | 2012 |
| Wise Coaches Limited | Transport & logistics | 1987 |
| Wise People Limited | Other services | 2022 |
| Wish Catering Limited | Hospitality | 2023 |
| Wish International Ltd | Information & communication | 2026 |
| Wisolo Ltd | Real estate | 2019 |
| Witham Brothers Limited | Transport & logistics | 1998 |
| Withdean Commercial Property Ltd | Real estate | 2016 |
| Within Sight Training Limited | Education | 2009 |
| Wkcheung Projects Limited | Information & communication | 2024 |
| Wlfx Marketing Studio Ltd | Professional & scientific | 2026 |
| WLP Media Limited | Health & social care | 2019 |
| WM Group Ltd | Hospitality | 2025 |
| Wmotion Consulting Ltd | Hospitality | 2024 |
| WMT Associates Ltd | Professional & scientific | 2009 |
| Woden Supply Limited | Wholesale & retail | 2025 |
| Wolf Data Systems Limited | Information & communication | 2019 |
| Wolfox Limited | Manufacturing | 2017 |
| Wolitsah Limited | Real estate | 2017 |
| Wolverine Finance Limited | Construction | 2022 |
| Wonderful Montessori Ltd | Wholesale & retail | 2025 |
| Wonderful Thinking Ltd | Professional & scientific | 2016 |
| Wonderlust Film and TV Limited | Arts & recreation | 2021 |
| WOO Express Limited | Wholesale & retail | 2024 |
| Wood & Associates LLP | | 2007 |
| Wood and Wire Joinery Ltd | Manufacturing | 2019 |
| Woodbine Padgett Ltd | Real estate | 2024 |
| Woodbine Padgett Wines Ltd | Financial services | 2026 |
| Woodcote Corner Ltd | Administrative & support | 2016 |
| Woodhall Consulting Ltd | Professional & scientific | 2019 |
| Woodhart (4 Telscombe Road) Ltd | Real estate | 2024 |
| Woodhill Dental Limited | Health & social care | 2022 |
| Woodhill Property Limited | Real estate | 2026 |
| Woodhouse Solar Limited | Energy | 2015 |
| Woodingdean Food CIC | Wholesale & retail | 2023 |
| Woodley House Holidays Ltd | Hospitality | 2026 |
| Woodruff Billing Ltd | Professional & scientific | 2022 |
| Woods Structural Engineering Ltd | Professional & scientific | 2021 |
| Woohoo Education Ltd | Information & communication | 2021 |
| Woopromotions Ltd | Arts & recreation | 2025 |
| Wordgirl Ltd | Professional & scientific | 2013 |
| Workshell Ltd | Information & communication | 2012 |
| World of Select Ltd | Information & communication | 2011 |
| World of Wheels Club Ltd | Arts & recreation | 2025 |
| World of Words Limited | Information & communication | 2013 |
| Worldvoices Ltd | Information & communication | 2020 |