| Stokkøya Eiendom AS | Real estate | 2018 |
| Stoksund Kapital AS | | 2025 |
| Stoksundferja AS | Manufacturing | 2012 |
| Stoksvoll AS | | 2020 |
| Stomispesialisten AS | Wholesale & retail | 2018 |
| Stoppeffekt AS | Professional & scientific | 2018 |
| Storage Solutions AS | Real estate | 2021 |
| Storbukken AS | Manufacturing | 2017 |
| Store Opplevelser AS | Real estate | 2022 |
| Storeskjeret AS | | 2022 |
| Storfosen Gods AS | Real estate | 2011 |
| Storgata 20-22 Eiendom AS | Real estate | 2021 |
| Storhaugen Holding AS | | 2025 |
| Storhaugstien 26B AS | Real estate | 2021 |
| Storheia Invest AS | Professional & scientific | 2014 |
| Storlia Eiendom AS | Financial services | 2005 |
| Storm Boligutleie AS | Real estate | 2021 |
| Storm Holding AS | Construction | 2018 |
| Storm Programutvikling Ans | Information & communication | 1994 |
| Storm Senteret AS | Real estate | 2021 |
| Stormyra Miljøstasjon AS | Water & waste | 2011 |
| Storoksen Invest AS | | 2012 |
| Storskarven Holding AS | | 2026 |
| Storsola AS | Real estate | 2024 |
| Storstrømmen AS | | 2022 |
| Storvika Invest AS | Real estate | 2010 |
| Storybits AS | Information & communication | 2020 |
| Storyteller Da | Arts & recreation | 2004 |
| Storytelling Media AS | Information & communication | 2009 |
| Storø Invest AS | Wholesale & retail | 2005 |
| Storøy Invest AS | Real estate | 2017 |
| Strada Holding AS | Wholesale & retail | 2018 |
| Strand Holding AS | Manufacturing | 1989 |
| Strand Mølster Holding AS | | 2021 |
| Strandplast AS | Manufacturing | 2008 |
| Strandveien 100 AS | Real estate | 2025 |
| Strandveien 43 Eiendom AS | Real estate | 2021 |
| Strandveien 43 Holding AS | Real estate | 2018 |
| Strandveien Auto AS | Other services | 1995 |
| Strandveiparken Eiendom AS | Real estate | 2008 |
| Strandveiparken Utvikling AS | Real estate | 2020 |
| Strandveiutsikten AS | Real estate | 2017 |
| Strange Brew Holding AS | Information & communication | 2017 |
| Strange Brew Nordic AS | Information & communication | 2015 |
| Strategicom AS | Real estate | 2009 |
| Straum Invest AS | | 2025 |
| Streamline Marketing AS | Professional & scientific | 2025 |
| Strekmann AS | Information & communication | 2013 |
| Strikkbar AS | Wholesale & retail | 2026 |
| Strikksom Da | Information & communication | 2019 |
| Strinda Dyreklinikk AS | Professional & scientific | 2024 |
| Strinda Dyreklinikk Eiendom AS | Real estate | 2024 |
| Strinda Eiendom AS | Real estate | 2002 |
| Strinda Entreprenør AS | Construction | 2020 |
| Strinda Legesenter AS | Health & social care | 2008 |
| Strinda Næring AS | Real estate | 2021 |
| Strinda Rørservice AS | Wholesale & retail | 2013 |
| Strindheim Kunstgress AS | Arts & recreation | 1990 |
| Strindheim Taxi AS | Transport & logistics | 2026 |
| Strindvegen 12 AS | Real estate | 2023 |
| Stro Holding AS | | 2024 |
| Structor Trondheim AS | Professional & scientific | 2018 |
| Strumke AS | Information & communication | 2024 |
| Strå & Spire AS | Wholesale & retail | 2025 |
| Ström Invest AS | Wholesale & retail | 2022 |
| Strøfin AS | Wholesale & retail | 2024 |
| Strøm Kapital AS | | 2026 |
| Strømsnes Kommunikasjon AS | Professional & scientific | 2018 |
| Strømsnes+ AS | Professional & scientific | 2000 |
| Strømsparerne AS | Education | 2020 |
| Strømsveien 81 Holding AS | Real estate | 2021 |
| Strømsveien Oslo Ans | Real estate | 1989 |
| Stst Holding AS | | 2025 |
| Stubban Finans AS | | 2005 |
| Stubban Holding AS | | 2018 |
| Stubø Holding AS | Arts & recreation | 2021 |
| Stuckrath Eiendom AS | Real estate | 1999 |
| Studbud Trondheim AS | Transport & logistics | 2017 |
| Studentmediene I Trondheim AS | Information & communication | 1988 |
| Studentnaustet AS | Real estate | 2025 |
| STUDENTPORTAL1 Ans | Professional & scientific | 2011 |
| Studersmart AS | Education | 2024 |
| Studi O Intercoiffure AS | Other services | 2016 |
| Studio 26 AS | Hospitality | 2012 |
| Studio 7011 AS | Wholesale & retail | 2005 |
| Studio Aukan AS | Other services | 2022 |
| Studio Beve AS | Other services | 2023 |
| Studio Elle Melle AS | Professional & scientific | 2014 |
| Studio Gauntlet AS | Information & communication | 2018 |
| Studio Meadow AS | Other services | 2022 |
| Studio Mini Super AS | Professional & scientific | 2018 |
| Studio Sax AS | Other services | 2002 |
| Studio Sjellsand AS | Professional & scientific | 2018 |
| Studio Skjeldam AS | Arts & recreation | 2013 |
| Studio Stenberg Holding AS | | 2021 |
| Studio Ultra Sun Ans | Other services | 2003 |
| Studiodrift AS | Information & communication | 1983 |
| Stuedal AS | Real estate | 2006 |
| Stundom Records Da | Information & communication | 2019 |
| Sturdy Coaching AS | Education | 2022 |