| Self Catering Arran Limited | Hospitality | 2017 |
| Simply Housekeeping Arran Ltd | Administrative & support | 2021 |
| Slav Building Services Limited | Construction | 2020 |
| STARTUP4TEN Limited | Professional & scientific | 2019 |
| Tarsuinn Cottages Ltd | Real estate | 2020 |
| Taste of Arran Ltd. | Wholesale & retail | 2002 |
| TEF Joinery Ltd | Construction | 2025 |
| THE Arran Collective Ltd | Hospitality | 2021 |
| THE Arran Gift Box Company Limited | Wholesale & retail | 2017 |
| THE Arran Lodge Limited | Hospitality | 2016 |
| THE Arran Pioneer Project CIC | Agriculture & fishing | 2020 |
| THE Arran Tablet Company Limited | Manufacturing | 2012 |
| THE Arran Theatre and Arts Trust | Arts & recreation | 1989 |
| THE Arran Trust | Other services | 2011 |
| THE Clyde Model Dockyard Limited | Wholesale & retail | 2001 |
| THE Fairways at Shiskine Ltd | Hospitality | 2025 |
| THE Fifth Floor Agency Ltd | Professional & scientific | 2021 |
| THE French FOX Food Company Ltd | Hospitality | 2020 |
| THE Fresh Stuff Ltd | Wholesale & retail | 2019 |
| THE Isle of Arran Candle Company Ltd | Manufacturing | 2022 |
| THE Scottish School of Herbal Medicine Ltd. | Administrative & support | 2004 |
| THE Shore Arran Ltd | Hospitality | 2018 |
| THE Tartan Tablet Company on Arran Limited | Manufacturing | 2013 |
| Theweehoose Ltd | Hospitality | 2022 |
| THREE60 Project Consultancy Ltd | Professional & scientific | 2021 |
| Thunderguy Farm Partnership | | 1991 |
| Torrylinn Developments Limited | Manufacturing | 2021 |
| Touch-Less Hygiene UK Ltd | Administrative & support | 2005 |
| Touchless Innovation Ltd | Administrative & support | 2015 |
| Townsend Farms | | 1995 |
| Vision Digital Limited | Information & communication | 2016 |
| Visitarran C.I.C. | Administrative & support | 2007 |
| Weirs Garage Ltd | Wholesale & retail | 2023 |
| Whitefield Farmers | | 1994 |
| WHO Studios Limited | Professional & scientific | 2016 |
| Wild Bathing Ltd | Administrative & support | 2025 |
| Wild Ecosse Ltd | Hospitality | 2025 |
| Wild Isle Venison Ltd | Manufacturing | 2025 |
| Wildertimes Ltd | Administrative & support | 2024 |
| Wildwood Croft Ltd | Agriculture & fishing | 2022 |
| William Bennett Plumbing Limited | Construction | 2009 |
| WIN WIN Business Ltd | Professional & scientific | 2018 |
| Winter IS Coming Ltd | Administrative & support | 2020 |
| WKS Construction Ltd | Construction | 2025 |
| Wolfpack PUB Group Limited | Hospitality | 2019 |
| Woodside Arran CIC | Agriculture & fishing | 2017 |