| Westbury Park Engineering Limited | Manufacturing | 1998 |
| Westfields Limited | Water & waste | 1998 |
| Westwells Paddock Limited | Real estate | 2021 |
| Weybourne Corporate Trustee Limited | Financial services | 2019 |
| Weybourne Limited | Financial services | 2016 |
| Weybourne Management Limited | Professional & scientific | 2013 |
| Whale and Dolphin Conservation | Other services | 1992 |
| White Horse Cars Limited | Transport & logistics | 2003 |
| White Horse Design and Build Ltd. | Construction | 1998 |
| Whiteoxmead Publications Limited | Information & communication | 1996 |
| Whiteparish Financial Services Limited | Professional & scientific | 2007 |
| Willis & Company (Town Planning) Limited | Professional & scientific | 1998 |
| Wilmingtons Estate Agents Ltd. | Professional & scientific | 1997 |
| Wilton Finance Limited | Administrative & support | 1993 |
| Wiltshire Farm Foods Limited | Extraterritorial | 1985 |
| Wiltshire Publications Ltd. | Information & communication | 1991 |
| Wiltshire Rural Music School Limited | Education | 1965 |
| Wincanton UK Limited | Transport & logistics | 2005 |
| Winchcombe Estates Ltd | Administrative & support | 2004 |
| Wireless International Consultants Limited | Other services | 2015 |
| Womad Festivals Limited | Administrative & support | 2009 |
| Woolley & Wallis Salisbury Salerooms Limited | Administrative & support | 1994 |
| Woolrych Computer Services Ltd | Other services | 2003 |
| Y2K Hair and Beauty Limited | Other services | 1999 |
| Yarnbury Castle Limited | Extraterritorial | 2007 |
| Yeoman Tree Specialists Limited | Agriculture & fishing | 2005 |
| Yiyi Solutions Limited | Health & social care | 2018 |
| Zeals Motor Company Limited | Wholesale & retail | 2007 |
| Zinc Industrial Processing Limited | Manufacturing | 2007 |