| Samurai Tree Care Limited | Administrative & support | 2024 |
| Sango Sands Oasis Ltd. | Hospitality | 2003 |
| Scotrain Ltd | Education | 2013 |
| Scott Vetters Engineering Ltd | Professional & scientific | 2016 |
| Scourie Filling Station Ltd | Wholesale & retail | 2025 |
| Seed to Supper CIC | Hospitality | 2026 |
| Senlac Hill Consulting Ltd | Professional & scientific | 2025 |
| Skymount Limited | Wholesale & retail | 2001 |
| Squiggle Web Design Ltd | Extraterritorial | 2025 |
| Stempster Property Ltd | Extraterritorial | 2026 |
| Streamside Facility Management Ltd | Manufacturing | 2019 |
| Stuart Anderson Limited | Professional & scientific | 1996 |
| Sutherland Community Seaweed CIC | Agriculture & fishing | 2025 |
| THE Highland Scullery Ltd | Hospitality | 2025 |
| THE Loch Assynt Centre CIC | Education | 2026 |
| THE Loch Clash Fish Company Limited | Wholesale & retail | 1965 |
| Titan Collective Ltd | Professional & scientific | 2025 |
| Transport for Tongue Limited | Transport & logistics | 2012 |
| Twentyfourdotdirect Limited | Wholesale & retail | 2024 |
| Visit Sandwood Limited | Hospitality | 2017 |
| Voluntary Groups Sutherland | Health & social care | 1994 |
| Wild North Watersports Limited | Arts & recreation | 2025 |
| Wilson Groundworks & Landscaping Ltd | Construction | 2020 |
| Xstco CAD FAB Ltd | Manufacturing | 2019 |
| Xstco Stone Ltd | Mining & quarrying | 2019 |
| Xstco Trailers Ltd | Manufacturing | 2018 |