| Sunn Investering Ltd Nuf | Professional & scientific | 2006 |
| Superclub Studio AS | Professional & scientific | 2024 |
| Supergreen AS | Information & communication | 2014 |
| Suphan Investment AS | | 2010 |
| Suphan Kitchen AS | Hospitality | 2022 |
| Surfacore AS | Administrative & support | 2014 |
| Sushi Bar Otta AS | Hospitality | 2021 |
| Sushi Haugesund AS | Hospitality | 2014 |
| Svarverud Bang Invest AS | Financial services | 2014 |
| Svebakken Terrasse AS | Real estate | 2011 |
| Svecon AS | Professional & scientific | 1989 |
| Svehaugstemmen 6 AS | Real estate | 2014 |
| Svein Erik Utleie AS | Administrative & support | 2015 |
| Sveinavik Invest AS | Real estate | 2014 |
| Sveindal Holding AS | Professional & scientific | 2015 |
| Sveinung Dalen Subsea Solutions AS | Professional & scientific | 2017 |
| Sveio Blikk Og Tak AS | Construction | 2025 |
| Sveio Lavpris AS | Wholesale & retail | 1996 |
| Sveio Utleigebygg AS | Real estate | 1984 |
| Sverre Sørhaug Eiendom Og Utleie AS | Real estate | 2020 |
| Sverre Øveraas Eiendom AS | Real estate | 1987 |
| Sveta AS | Real estate | 2019 |
| Svoldergaten AS | Real estate | 1983 |
| Swell Invest AS | | 2024 |
| Syd Vest Dykkersenter Ans | | 1993 |
| Sydvest Eiendom AS | Real estate | 2013 |
| Sydvest Tak AS | Construction | 2012 |
| Sykepleierinnen AS | Health & social care | 2020 |
| Sykkelshop Haugesund AS | Wholesale & retail | 2017 |
| Syla Bil AS | Transport & logistics | 2017 |
| Synergi Bolig AS | Real estate | 2015 |
| Synergia Advisors Holding AS | Professional & scientific | 2005 |
| Synkro AS | Information & communication | 2021 |
| Synnevåg Eiendom AS | Real estate | 1997 |
| Syriana Holding AS | Wholesale & retail | 2023 |
| Syriana Matbutikk AS | Wholesale & retail | 2023 |
| Syseg AS | Transport & logistics | 2007 |
| Sæbø Holding AS | Real estate | 2005 |
| Sør Retail AS | Wholesale & retail | 2018 |
| Sørhaug Dame Og Herrefrisør AS | Other services | 2001 |
| Sørhaug Holding AS | Real estate | 2016 |
| Sørhaug Invest AS | Financial services | 2020 |
| Sørhauggata 114 AS | Real estate | 2018 |
| Sørhauggata 137 AS | Real estate | 2022 |
| Sørhauggata 152 AS | Real estate | 2019 |
| Sørhauggata 196 AS | Real estate | 2022 |
| Sørhauggaten 139 Da | Real estate | 2005 |
| Sørhauggaten Utleiebygg AS | Real estate | 1995 |
| Sørhauggt 88/86 AS | Real estate | 2014 |
| Sørvaag Salg AS | Wholesale & retail | 2025 |
| T Jacobsen AS | Real estate | 2003 |
| T Langhelle Invest AS | Professional & scientific | 2021 |
| T Risanger Holding AS | | 2025 |
| T Stærk AS | Real estate | 2017 |
| T&S Property Holding AS | Real estate | 2024 |
| T-H Sushi AS | Hospitality | 2020 |
| T. Brandt Holding AS | Professional & scientific | 2000 |
| T. G. Isdahl Holding AS | | 2023 |
| T. Sampson AS | Wholesale & retail | 2005 |
| T/C & Partners AS | Transport & logistics | 1990 |
| T/C Haugesund AS | Real estate | 2016 |
| T/C Invest AS | Real estate | 2016 |
| T/C Management AS | Transport & logistics | 2021 |
| Ta-Holding AS | | 2005 |
| Tada AS | Professional & scientific | 2005 |
| Tada Holding AS | Professional & scientific | 2014 |
| Takahe AS | Professional & scientific | 2023 |
| Takgrossisten.Com AS | Wholesale & retail | 2025 |
| Taksthuset Haugesund AS | Professional & scientific | 2017 |
| Taksthuset Vest AS | Real estate | 2024 |
| Takstmann Harald Ingebrigtsen AS | Real estate | 2024 |
| Talge AS | Construction | 2021 |
| Talisman Consulting AS | Professional & scientific | 2006 |
| Tanatorget Eiendom Holding AS | Real estate | 2024 |
| Tanngården Haugesund AS | Health & social care | 2023 |
| Tanngården Haugesund Eiendom AS | Real estate | 2023 |
| Tanngården Haugesund Holding AS | Health & social care | 2023 |
| Tannhelsehuset Haugesund AS | Health & social care | 2005 |
| Tannhelsehuset Haugesund Produkter AS | Health & social care | 2024 |
| Tannlege Anna Pugerud AS | Health & social care | 2020 |
| Tannlege Erik K. Mauland AS | Health & social care | 2014 |
| Tannlege Gregor Volz AS | Health & social care | 2025 |
| Tannlege Karin Holmgard AS | Health & social care | 2005 |
| Tannlege Siv Storesund AS | Health & social care | 2019 |
| Tannlegekontoret Fides AS | Health & social care | 2000 |
| Tannlegene Lande AS | Health & social care | 1999 |
| Tannpleier Monica Håland Våg AS | Health & social care | 2024 |
| Tante Ulrika AS | Wholesale & retail | 2020 |
| Tapro AS | Manufacturing | 1990 |
| Taravik Invest AS | | 2025 |
| Tasima AS | Professional & scientific | 2012 |
| Tasty Haugesund AS | Hospitality | 2024 |
| Tattoo Incorporated AS | Other services | 2024 |
| Taxon Takst AS | Real estate | 2026 |
| TB Eiendomsforvaltning AS | Real estate | 2024 |
| TB Eiendomsutvikling AS | Real estate | 2019 |
| TB Informasjonsteknologi AS | Information & communication | 2021 |
| TB Økonomi AS | Professional & scientific | 2005 |
| TBT AS | Real estate | 2005 |
| TD Personell AS | Administrative & support | 2016 |