| Solligården Eiendomsutvikling AS | Real estate | 2004 |
| Solneset Syd 1 AS | Real estate | 2012 |
| Solnesset Eiendom AS | Real estate | 2007 |
| Solomon Holdings AS | | 2026 |
| Solstadr AS | Information & communication | 2025 |
| Solstrand Kystfiske AS | Agriculture & fishing | 2020 |
| Solstrandvegen 19 AS | Real estate | 2023 |
| Solstrandvegen 25-29 AS | Real estate | 2008 |
| Solstrandvegen 31 AS | Real estate | 2022 |
| Solstrandvegen AS | Real estate | 2026 |
| Soltind AS | Construction | 2006 |
| Sommarøy Arctic Eiendom AS | Real estate | 1986 |
| Sommerbakk AS | Real estate | 2024 |
| Sommernes Eiendom AS | Real estate | 2016 |
| Sonar Film AS | Information & communication | 2017 |
| Sondre AS | Wholesale & retail | 2012 |
| Sonora AS | Professional & scientific | 2005 |
| Sorgenfri 5 AS | Real estate | 2023 |
| Sorgenfri Eiendom AS | Real estate | 2025 |
| Soria Moria Holding Tromsø AS | Transport & logistics | 2002 |
| Sorjo AS | Construction | 2010 |
| Sortland Handelspark AS | Real estate | 2023 |
| Spaceloop AS | Information & communication | 2024 |
| Spar Invest AS | | 2025 |
| Sparebank 1 Finans Nord-Norge AS | Financial services | 1980 |
| Sparebank 1 Gruppen AS | Financial services | 1995 |
| Sparebank 1 Nord-Norge | Financial services | 1989 |
| Sparebank 1 Nord-Norge Portefølje AS | Financial services | 1984 |
| Sparebank 1 Regnskapshuset Nord-Norge AS | Professional & scientific | 1989 |
| Spartano AS | Wholesale & retail | 2026 |
| Spaun Holding AS | | 2026 |
| Spe Eiendom AS | | 2009 |
| Speedo Eiendom AS | Real estate | 1993 |
| Sport 1 Tromsø - Jekta AS | Wholesale & retail | 2023 |
| Sportshjørnet Da | Wholesale & retail | 1998 |
| Språksenteret AS | Professional & scientific | 2018 |
| Sr-Eiendomsutleie AS | Real estate | 2012 |
| Sr-Invest AS | Real estate | 2005 |
| Ssa-Holding AS. | | 2026 |
| SSK Kantine AS | Hospitality | 2015 |
| Stadly Biodry AS | Energy | 2025 |
| Stajo Utleie AS | Hospitality | 2020 |
| Stakke Kontor AS | Real estate | 2019 |
| Stakke Utvikling AS | Real estate | 2019 |
| Stakkevollvegen 11 AS | Real estate | 2019 |
| Stakkevollvegen 132 AS | | 2026 |
| Stakkevollvegen 301 AS | Real estate | 2021 |
| Stakkevollvegen 33 AS | Real estate | 2020 |
| Stakkevollvegen 335 AS | Real estate | 2016 |
| Stakkevollvegen 35/37 AS | Real estate | 2019 |
| Stakkevollvegen 39 AS | Real estate | 2019 |
| Stakkevollvegen 41 AS | Real estate | 2019 |
| Stakkevollvegen Eiendom AS | Real estate | 2014 |
| Stakkevollveien 297 AS | Real estate | 2020 |
| Stakkevollveien 48-50 AS | Real estate | 2014 |
| Stakkevollveien Handleri Da | Wholesale & retail | 1996 |
| Stalsbergtunet AS | Real estate | 2025 |
| Stamcellehuset Ortopediske Klinikk AS | Professional & scientific | 2019 |
| Stand-Up Tromsø Da | Administrative & support | 2024 |
| Star P Holding AS | | 2025 |
| Starlight Holding AS | | 2025 |
| Stas Frisør AS | Other services | 2020 |
| Stauren Invest AS | | 2025 |
| Stay Here Tromsø AS | Hospitality | 2023 |
| Stay Tromso AS | Real estate | 2023 |
| Staying AS | Real estate | 2018 |
| Staying Utleie AS | Real estate | 2018 |
| Steamed Hams AS | | 2023 |
| Steget Videre Skomakeri AS | Other services | 2025 |
| Stein Bergan AS | Professional & scientific | 1994 |
| Stein Sørensen Persontransport Din Taxi AS | Transport & logistics | 1998 |
| Stein Tore Gustavsen AS | Real estate | 2011 |
| Steinly Hydraulikk AS | Manufacturing | 2016 |
| Steinly Marin Service AS | Manufacturing | 2018 |
| Steinsentre AS | Wholesale & retail | 1998 |
| Stella Nexus AS | Professional & scientific | 2016 |
| Stella Polaris Norway AS | Manufacturing | 2004 |
| Stenersen Frisør AS | Other services | 1991 |
| Stenger & Ibsen Construction Norge AS | Construction | 2005 |
| Stenhaug Holding AS | | 2025 |
| Steni Eiendom AS | Real estate | 2001 |
| Stensland & Fossland Scenekompani Da | Arts & recreation | 2021 |
| Stenvold Eiendom AS | Hospitality | 2025 |
| Stevefisk AS | Financial services | 1996 |
| Stevefisk Holding AS | | 2020 |
| STG 25 AS | Real estate | 2018 |
| STG 25 II AS | Real estate | 2019 |
| STG 26 AS | Real estate | 2023 |
| Sthafa Invest AS | Real estate | 2022 |
| Stigen Keramikk AS | Manufacturing | 2024 |
| Stili Eiendom AS | Real estate | 2015 |
| Stili Frisør AS | Other services | 2014 |
| Stine Åsli AS | Professional & scientific | 2020 |
| Stipe Invest AS | Real estate | 2016 |
| STJ Holding AS | Wholesale & retail | 2005 |
| Stofflykke AS | Wholesale & retail | 2016 |
| Store Norske Fiskekompani AS | Hospitality | 1996 |
| Storelva AS | Real estate | 2015 |
| Storelvbakken 5 Eiendom AS | Real estate | 2014 |
| Storelvtunet 1 AS | Real estate | 2018 |