| William Gordon Property Limited | Real estate | 2023 |
| Wilstons of Avebury Limited | Manufacturing | 2016 |
| Wiltshire Concrete Limited | Manufacturing | 2017 |
| Wiltshire Music School Ltd | Education | 2015 |
| Wiltshire Partridges Limited | Administrative & support | 2001 |
| Wiltshire ROD & GUN Ltd | Wholesale & retail | 2007 |
| Wiltshire Truffles Limited | Agriculture & fishing | 2014 |
| Windsor Clive International Limited | Real estate | 1986 |
| Winford Land Ltd | Construction | 2019 |
| Winsor Birch Limited | Wholesale & retail | 2023 |
| Winterbourne Construction Services Ltd | Construction | 2025 |
| Witheford Equine Limited | Arts & recreation | 1998 |
| Wittsend Plumbing Limited | Construction | 2012 |
| WNM Consulting Limited | Professional & scientific | 2025 |
| Wolsey Foods Limited | Professional & scientific | 1963 |
| Wop-Wops Ltd | Wholesale & retail | 2021 |
| Worn Preloved Clothing Ltd | Wholesale & retail | 2020 |
| Wray IT Consulting Limited | Information & communication | 2009 |
| Wynkoop Consulting Ltd | Professional & scientific | 2023 |
| Wyvern/Gro Entertainment Ltd | Arts & recreation | 1988 |
| Xagonbuilding Ltd | Construction | 2017 |
| Yodaglada Limited | Manufacturing | 2026 |
| York Lodge (Marlborough) Management Company Ltd | Households | 2015 |
| Yorke Farming Ltd | Agriculture & fishing | 2015 |
| YOU Need a PA Ltd | Other services | 2013 |
| You.Nique Business Solutions Limited | Professional & scientific | 2001 |
| Your Place Homes Ltd | Real estate | 2024 |
| Your Place Property & GAS Ltd | Construction | 2016 |
| YPN Consultancy Ltd | Information & communication | 2026 |
| Z Bond Nominees Ltd | Professional & scientific | 2012 |
| ZEE DEE BEE Limited | Administrative & support | 2026 |
| Zest & Zing Limited | Wholesale & retail | 2016 |
| Zonic Corporation Limited | Administrative & support | 2002 |
| Zoria Beauty Ltd | Other services | 2011 |
| Zummo London Limited | Wholesale & retail | 2001 |